Add build system, remove dependency on glib, add TAP library

This commit...

 * adds an automake-based system.
 * removes glib dependencies from the library code (i.e. not from the tests),
   replacing them with home-grown code.
 * sets up the tests to run using the TAP library [1].

[1] https://github.com/shlomif/libtap-prev

Signed-off-by: Simon Marchi <simon.marchi@efficios.com>