Fixing autobahn test 7.1.5, when a connection close, is a valid frame (even if previous fragment frame was not final)
Fixing autobahn test 6.4.2 due to utf-8 validation that should reject any 0xF4 0x90 ... since any following bytes would result into out of range codepoint
Code cleaning
Added support for utf-8 validation at the data chop level, instead of the non strict fragment level.
Added WS_FRAME.check_utf_8_validity_on_chop: BOOLEAN .. in order to enable or disable this checking at chop level
  since it impact performances for now (TODO: improve this part)
Merge branch 'review20140109' of https://github.com/jocelyn/WebSocket into ws_review

Conflicts:
	server/src/http_request_handler_i.e
For now, disable utf-8 checking at chop level, since this is more at "chunk" level in our implementation.
Merge branch 'review20140109' of https://github.com/jocelyn/WebSocket into ws_review