Update to uSockets v0.3.1

Update uSockets, improve Makefile

Rather use last byte to determine what to do

Loop over data in chunks of 0-255 while mocking

Update to uSockets v0.2.0

Update uSocketsMock.c to the 0.2.0 interfaces

Add files via upload

Quick-fix GCC build

Guarantee to end http parsing after websocket upgrade

Also fuzz handshakes