Fix #107 - Installing on Mono 3.0.4
Fix #107 - Installing on Mono 3.0.4

@migueldeicaza says "The problem is that we installed a pkg-config
program in /usr/bin which only looked up at the Mono database of
packages, as it was a symlink to the one in
/Library/Frameworks/Mono.framework This caused problem for people that
either had their own, or were using popular Unix install systems like
Homebrew or MacPorts. The correct fix is to detect if
/Library/Frameworks/Mono.framework/Versions/Current/bin/pkg-config
exists, if it does, use that, instead use /usr/bin/pkg-config"

BillHally/FSharp.Compiler.Service,directhex/fsharp,bleis-tift/FSharp.Compiler.Service,wk-j/fsharp,7sharp9/fsharp,In2TheWild/fsharp,jeroldhaas/FSharp.Compiler.Service,matthid/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,matthid/FSharp.Compiler.Service,eloraiby/fsharp,Heather/fsharp,Heather/fsharp,rojepp/FSharp.Compiler.Service,yever/FSharp.Compiler.Service,0x53A/FSharp.Compiler.Service,alfonsogarciacaro/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,jeroldhaas/FSharp.Compiler.Service,mafiya69/fsharp,fsharp/fsharp,rolfbjarne/fsharp,rojepp/FSharp.Compiler.Service,alfonsogarciacaro/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,matthid/FSharp.Compiler.Service,forki/fsharp,alexischr/fsharp,sergey-tihon/FSharp.Compiler.Service,forki/FSharp.Compiler.Service,alfonsogarciacaro/FSharp.Compiler.Service,enricosada/fsharp,0x53A/FSharp.Compiler.Service,bleis-tift/FSharp.Compiler.Service,0x53A/FSharp.Compiler.Service,BillHally/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service,eloraiby/fsharp,rneatherway/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,alexischr/fsharp,enricosada/fsharp,forki/FSharp.Compiler.Service,In2TheWild/fsharp,directhex/fsharp,vasily-kirichenko/FSharp.Compiler.Service,fsharp/fsharp,Jand42/FSharp.Compiler.Service,alexischr/fsharp,ncave/FSharp.Compiler.Service,vasily-kirichenko/FSharp.Compiler.Service,yever/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,forki/fsharp,dsyme/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service,fsharp/fsharp,wk-j/fsharp,vasily-kirichenko/FSharp.Compiler.Service,rojepp/FSharp.Compiler.Service,mafiya69/fsharp,sergey-tihon/FSharp.Compiler.Service,forki/FSharp.Compiler.Service,sergey-tihon/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,rolfbjarne/fsharp,7sharp9/fsharp,cloudRoutine/FSharp.Compiler.Service,rneatherway/FSharp.Compiler.Service