Porting to last libwebsocket version in git repository

Hello,
I've been trying to do a example-client-sharedCanvas.
It crashed when receiving a lot of points at a time, with this error:
```
zlib error inflate -3 
extension reports fatal error
```
After trying to track that bue, I decided to get the last libwebsocket version, here:
http://git.libwebsockets.org/cgi-bin/cgit/libwebsockets/
It fixed the bug, and it is a lot faster than the previous version that was used in ofxLibwebsockets.
It used to take about 8 seconds to launch any of the examples provided. Now it's instant.

However, the lib changed a bit, so I had to change the ofxLibwebsockets too.

Some methods needed more arguments, (context, socket...)
But the main change is that broadcast doesn't exist anymore: http://git.libwebsockets.org/cgi-bin/cgit/libwebsockets/commit/test-server/test-server.c?id=6f520a5195defcb7fc69c669218a8131a5f35efb

I've put the new static lib file into the linux64 folder.
All folders needs to be updated : osx, win32, linuxarmv61...
Let me know if you need help for some systems.