added default image to demo to silence xcode warning
silenced warnings for mac demo
added arrayFromJSONWithError convenience method
Xcode 4.6 settings update
remove myself from code signing settings
replaced NSNumber-specific check with cleaner polymorphic call to [val urlEncodedString]
isValueAcceptable is now a plain function with a static array of class objects to avoid excessive allocations for each check
Merge pull request #6 from gwk/master

arrayFromJSONWithError: plus small fixes for Mac