Add an interactive evdev test

Add an interactive evdev test

The program reads key events from evdev input devices, puts them through
the library and prints some information about them. It's nice for
experimenting, quick testing and trying to break it with random stuff
(already found some!).

It is called "interactive" for lack of a better name. It's a bit
hackish, but can easily be extended, made more portable etc, in the
future.

Signed-off-by: Ran Benita <ran234@gmail.com>
Conflicts:
	Makefile.am
	test/.gitignore