Fixed #167

Added two's complement masking for the close frame's reason code.
Merge pull request #169 from paulpdaniels/patch-1

Fixed #167
Merge branch 'master' of https://github.com/koush/AndroidAsync

# By paulpdaniels
# Via Koushik Dutta (1) and paulpdaniels (1)
* 'master' of https://github.com/koush/AndroidAsync:
  Fixed #167