Update SIL.rst to discuss @box types.
Update SIL.rst to discuss @box types.

Swift SVN r29773

atrick/swift,tinysun212/swift-windows,gottesmm/swift,alblue/swift,roambotics/swift,modocache/swift,zisko/swift,KrishMunot/swift,therealbnut/swift,LeoShimonaka/swift,tkremenek/swift,alblue/swift,huonw/swift,milseman/swift,OscarSwanros/swift,hughbe/swift,shajrawi/swift,ben-ng/swift,Ivacker/swift,felix91gr/swift,kentya6/swift,allevato/swift,jmgc/swift,Jnosh/swift,djwbrown/swift,cbrentharris/swift,emilstahl/swift,emilstahl/swift,brentdax/swift,deyton/swift,tjw/swift,Ivacker/swift,JaSpa/swift,practicalswift/swift,johnno1962d/swift,gottesmm/swift,xwu/swift,tkremenek/swift,gribozavr/swift,tkremenek/swift,tinysun212/swift-windows,kusl/swift,shahmishal/swift,xedin/swift,jtbandes/swift,airspeedswift/swift,MukeshKumarS/Swift,OscarSwanros/swift,amraboelela/swift,ben-ng/swift,JGiola/swift,johnno1962d/swift,brentdax/swift,ken0nek/swift,xwu/swift,huonw/swift,nathawes/swift,mightydeveloper/swift,swiftix/swift.old,glessard/swift,benlangmuir/swift,airspeedswift/swift,jmgc/swift,CodaFi/swift,natecook1000/swift,jtbandes/swift,stephentyrone/swift,ben-ng/swift,felix91gr/swift,milseman/swift,manavgabhawala/swift,adrfer/swift,hooman/swift,kusl/swift,milseman/swift,apple/swift,kperryua/swift,Jnosh/swift,khizkhiz/swift,amraboelela/swift,swiftix/swift,benlangmuir/swift,gribozavr/swift,austinzheng/swift,gottesmm/swift,Ivacker/swift,bitjammer/swift,therealbnut/swift,tkremenek/swift,huonw/swift,nathawes/swift,codestergit/swift,karwa/swift,felix91gr/swift,sschiau/swift,alblue/swift,danielmartin/swift,SwiftAndroid/swift,frootloops/swift,apple/swift,dduan/swift,apple/swift,jtbandes/swift,adrfer/swift,rudkx/swift,felix91gr/swift,adrfer/swift,hughbe/swift,Jnosh/swift,devincoughlin/swift,calebd/swift,SwiftAndroid/swift,frootloops/swift,frootloops/swift,gribozavr/swift,khizkhiz/swift,slavapestov/swift,karwa/swift,allevato/swift,djwbrown/swift,rudkx/swift,shahmishal/swift,practicalswift/swift,JGiola/swift,JaSpa/swift,uasys/swift,huonw/swift,tinysun212/swift-windows,djwbrown/swift,harlanhaskins/swift,mightydeveloper/swift,johnno1962d/swift,harlanhaskins/swift,manavgabhawala/swift,brentdax/swift,ken0nek/swift,kperryua/swift,gmilos/swift,kstaring/swift,OscarSwanros/swift,CodaFi/swift,zisko/swift,zisko/swift,jopamer/swift,sdulal/swift,glessard/swift,IngmarStein/swift,tkremenek/swift,JaSpa/swift,allevato/swift,kentya6/swift,MukeshKumarS/Swift,devincoughlin/swift,CodaFi/swift,uasys/swift,apple/swift,danielmartin/swift,sschiau/swift,hooman/swift,aschwaighofer/swift,russbishop/swift,SwiftAndroid/swift,aschwaighofer/swift,amraboelela/swift,harlanhaskins/swift,xedin/swift,atrick/swift,johnno1962d/swift,gmilos/swift,lorentey/swift,slavapestov/swift,russbishop/swift,MukeshKumarS/Swift,gregomni/swift,kentya6/swift,johnno1962d/swift,tardieu/swift,gribozavr/swift,parkera/swift,LeoShimonaka/swift,russbishop/swift,tkremenek/swift,tinysun212/swift-windows,glessard/swift,arvedviehweger/swift,roambotics/swift,stephentyrone/swift,jckarter/swift,benlangmuir/swift,modocache/swift,slavapestov/swift,calebd/swift,ahoppen/swift,harlanhaskins/swift,uasys/swift,gmilos/swift,danielmartin/swift,swiftix/swift,adrfer/swift,tardieu/swift,SwiftAndroid/swift,CodaFi/swift,JaSpa/swift,codestergit/swift,jopamer/swift,gottesmm/swift,karwa/swift,swiftix/swift,parkera/swift,kperryua/swift,deyton/swift,kstaring/swift,russbishop/swift,sdulal/swift,arvedviehweger/swift,ahoppen/swift,stephentyrone/swift,frootloops/swift,kusl/swift,calebd/swift,amraboelela/swift,zisko/swift,khizkhiz/swift,xwu/swift,uasys/swift,IngmarStein/swift,mightydeveloper/swift,kperryua/swift,swiftix/swift,airspeedswift/swift,roambotics/swift,jtbandes/swift,emilstahl/swift,hooman/swift,gmilos/swift,benlangmuir/swift,MukeshKumarS/Swift,shahmishal/swift,kentya6/swift,jopamer/swift,tardieu/swift,felix91gr/swift,OscarSwanros/swift,amraboelela/swift,jmgc/swift,deyton/swift,jopamer/swift,nathawes/swift,parkera/swift,airspeedswift/swift,codestergit/swift,rudkx/swift,arvedviehweger/swift,therealbnut/swift,xedin/swift,tardieu/swift,ahoppen/swift,Ivacker/swift,hughbe/swift,mightydeveloper/swift,gribozavr/swift,Jnosh/swift,felix91gr/swift,kstaring/swift,IngmarStein/swift,modocache/swift,kentya6/swift,gregomni/swift,modocache/swift,harlanhaskins/swift,therealbnut/swift,gregomni/swift,allevato/swift,slavapestov/swift,brentdax/swift,JGiola/swift,sschiau/swift,atrick/swift,xedin/swift,codestergit/swift,aschwaighofer/swift,KrishMunot/swift,tardieu/swift,devincoughlin/swift,shahmishal/swift,shajrawi/swift,danielmartin/swift,xedin/swift,djwbrown/swift,harlanhaskins/swift,milseman/swift,dduan/swift,manavgabhawala/swift,SwiftAndroid/swift,tkremenek/swift,lorentey/swift,bitjammer/swift,xwu/swift,benlangmuir/swift,shahmishal/swift,austinzheng/swift,gregomni/swift,parkera/swift,LeoShimonaka/swift,brentdax/swift,ahoppen/swift,nathawes/swift,brentdax/swift,practicalswift/swift,manavgabhawala/swift,calebd/swift,jtbandes/swift,LeoShimonaka/swift,Jnosh/swift,natecook1000/swift,SwiftAndroid/swift,OscarSwanros/swift,KrishMunot/swift,parkera/swift,swiftix/swift,parkera/swift,Ivacker/swift,gribozavr/swift,nathawes/swift,practicalswift/swift,dduan/swift,khizkhiz/swift,emilstahl/swift,return/swift,glessard/swift,kentya6/swift,manavgabhawala/swift,jckarter/swift,milseman/swift,austinzheng/swift,slavapestov/swift,emilstahl/swift,kstaring/swift,therealbnut/swift,apple/swift,sdulal/swift,airspeedswift/swift,calebd/swift,kusl/swift,shahmishal/swift,johnno1962d/swift,karwa/swift,swiftix/swift.old,JaSpa/swift,MukeshKumarS/Swift,gmilos/swift,sschiau/swift,JGiola/swift,djwbrown/swift,kentya6/swift,ahoppen/swift,uasys/swift,Jnosh/swift,shahmishal/swift,alblue/swift,hooman/swift,arvedviehweger/swift,bitjammer/swift,ken0nek/swift,kperryua/swift,cbrentharris/swift,aschwaighofer/swift,kentya6/swift,brentdax/swift,slavapestov/swift,swiftix/swift.old,calebd/swift,lorentey/swift,glessard/swift,sdulal/swift,lorentey/swift,dreamsxin/swift,glessard/swift,cbrentharris/swift,shajrawi/swift,zisko/swift,tjw/swift,swiftix/swift.old,JGiola/swift,cbrentharris/swift,OscarSwanros/swift,hughbe/swift,jopamer/swift,frootloops/swift,deyton/swift,tjw/swift,cbrentharris/swift,russbishop/swift,mightydeveloper/swift,atrick/swift,huonw/swift,austinzheng/swift,mightydeveloper/swift,sdulal/swift,codestergit/swift,OscarSwanros/swift,hooman/swift,aschwaighofer/swift,JaSpa/swift,bitjammer/swift,return/swift,practicalswift/swift,parkera/swift,danielmartin/swift,Ivacker/swift,sschiau/swift,gottesmm/swift,therealbnut/swift,JGiola/swift,swiftix/swift,parkera/swift,CodaFi/swift,stephentyrone/swift,amraboelela/swift,danielmartin/swift,natecook1000/swift,sschiau/swift,kusl/swift,rudkx/swift,apple/swift,hooman/swift,jckarter/swift,practicalswift/swift,lorentey/swift,codestergit/swift,deyton/swift,alblue/swift,swiftix/swift.old,slavapestov/swift,mightydeveloper/swift,alblue/swift,ken0nek/swift,Ivacker/swift,MukeshKumarS/Swift,mightydeveloper/swift,russbishop/swift,devincoughlin/swift,dduan/swift,jmgc/swift,shajrawi/swift,tinysun212/swift-windows,sdulal/swift,manavgabhawala/swift,swiftix/swift.old,djwbrown/swift,LeoShimonaka/swift,return/swift,adrfer/swift,jtbandes/swift,zisko/swift,devincoughlin/swift,dduan/swift,cbrentharris/swift,stephentyrone/swift,kperryua/swift,gregomni/swift,kstaring/swift,karwa/swift,ben-ng/swift,ben-ng/swift,CodaFi/swift,return/swift,kusl/swift,danielmartin/swift,xwu/swift,atrick/swift,uasys/swift,emilstahl/swift,karwa/swift,CodaFi/swift,ken0nek/swift,frootloops/swift,felix91gr/swift,devincoughlin/swift,tjw/swift,emilstahl/swift,benlangmuir/swift,xedin/swift,milseman/swift,zisko/swift,allevato/swift,return/swift,khizkhiz/swift,russbishop/swift,jckarter/swift,rudkx/swift,ken0nek/swift,jmgc/swift,lorentey/swift,natecook1000/swift,jopamer/swift,frootloops/swift,shajrawi/swift,hooman/swift,gribozavr/swift,jckarter/swift,emilstahl/swift,ken0nek/swift,tjw/swift,swiftix/swift.old,lorentey/swift,natecook1000/swift,nathawes/swift,bitjammer/swift,djwbrown/swift,natecook1000/swift,gregomni/swift,Ivacker/swift,devincoughlin/swift,amraboelela/swift,cbrentharris/swift,Jnosh/swift,tardieu/swift,austinzheng/swift,tardieu/swift,shajrawi/swift,tjw/swift,gottesmm/swift,IngmarStein/swift,airspeedswift/swift,stephentyrone/swift,arvedviehweger/swift,khizkhiz/swift,devincoughlin/swift,huonw/swift,swiftix/swift,practicalswift/swift,johnno1962d/swift,modocache/swift,sschiau/swift,KrishMunot/swift,adrfer/swift,swiftix/swift.old,stephentyrone/swift,manavgabhawala/swift,aschwaighofer/swift,allevato/swift,tjw/swift,khizkhiz/swift,LeoShimonaka/swift,IngmarStein/swift,SwiftAndroid/swift,karwa/swift,kstaring/swift,xedin/swift,codestergit/swift,JaSpa/swift,huonw/swift,shajrawi/swift,jmgc/swift,xwu/swift,therealbnut/swift,adrfer/swift,kstaring/swift,roambotics/swift,xwu/swift,jckarter/swift,harlanhaskins/swift,ahoppen/swift,kperryua/swift,sschiau/swift,KrishMunot/swift,karwa/swift,jckarter/swift,shahmishal/swift,austinzheng/swift,dduan/swift,arvedviehweger/swift,sdulal/swift,xedin/swift,MukeshKumarS/Swift,return/swift,aschwaighofer/swift,bitjammer/swift,arvedviehweger/swift,IngmarStein/swift,LeoShimonaka/swift,sdulal/swift,alblue/swift,practicalswift/swift,hughbe/swift,shajrawi/swift,gmilos/swift,nathawes/swift,deyton/swift,gottesmm/swift,jmgc/swift,uasys/swift,cbrentharris/swift,gmilos/swift,gribozavr/swift,calebd/swift,tinysun212/swift-windows,IngmarStein/swift,modocache/swift,milseman/swift,airspeedswift/swift,natecook1000/swift,roambotics/swift,ben-ng/swift,hughbe/swift,return/swift,tinysun212/swift-windows,jopamer/swift,deyton/swift,kusl/swift,dreamsxin/swift,allevato/swift,austinzheng/swift,dduan/swift,LeoShimonaka/swift,ben-ng/swift,rudkx/swift,KrishMunot/swift,roambotics/swift,modocache/swift,atrick/swift,hughbe/swift,lorentey/swift,kusl/swift,KrishMunot/swift,jtbandes/swift,bitjammer/swift