Add check support

Check is a unit testing framework for C.

All the QObjects have unit-tests and more will be written for the
future data types.

More info about check can be found at:

http://check.sourceforge.net/

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
