tests: add interface for running tests

This is the wayland's test-suite.
core: add generic macros

add macros: assertf (assert with formated output) and dbg (debug message)
core: add initial server code

This is code formerly written in my branch of wayland.
I just renamed functions and deleted some functionality (which will be
added in some later commit) to have more consistend commits
It can compile, although I dont know if it will work now
core: add client code

This is the core code for client, taken from my branch in wayland
Maybe not functional now, but compiles
headers: add header file

add wit.h which integrates server.h and client.h