Optional websocket user agent header support.
FileCallback onProgress >2GiB file support
Changed content length to be a long
Fix Classpath to line up with original
Merge pull request #154 from sst8696/master

Support files larger than 2GiB onProgress callback
Improve exception trace in SSL errors.
Switch from URI to Uri.

URI does not allow braces: {}, even though they are allowed in the spec.
It is also easier to build paths using a Uri instance.

Download/upload progress should be done with longs for large transfers.
Fix connection: close honoring
remove imports
watch for socket close, fix sdk version 8 method missing issue.
1.2.6
Fix AsyncServer.stop
Throw assertion if tap is not found PushParser.
Fixed #167

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

Fixed #167