Fix: platform names generated in Info.plist (DTSDKName and DTPlatformName)

Currently, Info.plist generated always has these values:

DTSDKName = iphoneos7.0
DTPlatformName = iphoneos

but for simulator builds, we really should have:

DTSDKName = iphonesimulator7.0
DTPlatformName = iphonesimulator

This, at least affects https://app.io, which requires simulator builds to be uploaded and checks for the value of DTSDKName.