Adding tests for analyzing WebSocket frames (not done yet).
Added parsing of multiframe messages and control frames.
wsmsg_get_message gets the message opcode (binary or text).
Moved dynamic data buffer implementation to util.c.
Added more tests and fixed bug with processing WebSocket messages.
Removed unnecessary Exit label.
Improved processing WebSocket frames and messages.
Removed websockframe.h and websockframe.c.
Now WebSocket frames and messages are processed in wsmessage.h/.c.
We have better conformance with RFC 6455: multiframe messages,
control messages.