Move test related code and the testsuite away from tests/ and make it a
proper subsystem.
The way tests were integrate in the tree was not obvious and actual
tests were intermixed with the testsuite code.
This will allow us to have trees with the testcode and without the
samples by just remove the folders tests/ and samples, needed for
isolating actual code from test/sample code.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
