Support for iPhone 5
Replaced NSString with NSURL

Direct support for NSURL makes it easier to Unit Test with file:// URLs
Added support for response text encoding

The response text encoding can be invaluable when creating an NSString
from NSData.
Merge branches 'phil' and 'master'
Removed unnecessary NSLog
Made responseTextEncoding property externally read-only
Merge pull request #2 from philippec/master

Improvements to JBContainedURLConnection