Return a fragmented frame when the input data is fragmented
Refactorice some code in message decoding
Refactoring in frame handling
Refactoring in frame decoding

* Added code to handle fragmented frames
Added some tests for fragmented frames
Complete fragmented frames
Fix a bug that make data to be considered as masked
Don't mark as fragmented frames which aren't
Fix handling of fragmented frames
Merge branch '2-handle-fragmented-websocket-frames' into develop