allow binding to IPv6 addresses
allow binding to IPv6 addresses

this fails, and is standard:
puma -b 'tcp://[2001:6e8:288::a]:9999'
this fails. and is non-standard but potentially acceptable to puma as port is mandatory argument:
puma -b 'tcp://2001:6e8:288::a:9999'

commit fixes the first issue, but is ghetto as hell, should be 1.8 .. 2.0 friendly
looker/puma,wallclockbuilder/puma,costi/puma,nathansamson/puma,zapnap/puma,snow/puma,respire/puma,tuvistavie/puma,costi/puma,wallclockbuilder/puma,snow/puma,wallclockbuilder/puma,jc00ke/puma,BenV/puma,kyledrake/puma,ngpestelos/puma,matthewd/puma,jc00ke/puma,costi/puma,tuvistavie/puma,jc00ke/puma,jbmyid/puma,jbmyid/puma,jbmyid/puma,arturocadena/puma,jbmyid/puma,matthewd/puma,matthewd/puma,prathamesh-sonpatki/puma,zBMNForks/puma,respire/puma,zapnap/puma,BenV/puma,zapnap/puma,puma/puma,ngpestelos/puma,looker/puma,snow/puma,respire/puma,tuvistavie/puma,snow/puma,respire/puma,jc00ke/puma,prathamesh-sonpatki/puma,unleashed/puma,kyledrake/puma,looker/puma,kyledrake/puma,matthewd/puma,eileencodes/puma,ngpestelos/puma,zBMNForks/puma,costi/puma,eileencodes/puma,zBMNForks/puma,ngpestelos/puma,nathansamson/puma,eileencodes/puma,eileencodes/puma,zapnap/puma,tuvistavie/puma,unleashed/puma,prathamesh-sonpatki/puma,unleashed/puma,nathansamson/puma,arturocadena/puma,puma/puma,looker/puma,puma/puma,puma/puma,unleashed/puma,wallclockbuilder/puma,nathansamson/puma,arturocadena/puma,prathamesh-sonpatki/puma,zBMNForks/puma,BenV/puma,arturocadena/puma,BenV/puma,kyledrake/puma