Instead of data received being an NSString, have it be NSData because converting...

Instead of data received being an NSString, have it be NSData because converting to NSString was actually causing problems and NSXMLDocument can take in NSData just fine

* Source/DebuggerConnection.m: Making all of the delivery functions use NSData not NSString
([DebuggerConnection _handshake:])
([DebuggerConnection _updateStatus:])
([DebuggerConnection _stackReceived:])
* Source/SocketWrapper.m|h: ditto
([SocketWrapper dataReceived:deliverTo:]): Now uses NSData
([SocketWrapper receive:]): Save ourselves some trouble and don't convert the data to NSString