Update to Xcode6

Fixed a number of issues in JSONKit.
Fixed some silly bugs in JPJsonWriter
The JPJson Lib for iOS has been updated for new archs.
Fixed potential memory leak in UIDevice-Hardware
Upgrade to Xcode6.1
Disable optimisation opportunity USE_OPTIMIZED_IMMUTABLE_CALLBACKS, since it causes memory leaks.
Upgrade for Xcode 6.1
Fix memory leak in CFDataBuffer

The move assignment and the assignment operator now correctly release an existing buffer.
Version 0.8.1
Merge branch 'ag-UpdateXcode6'