avocado: Move avocado.conf.settings -> avocado.settings

Let's simplify the program namespace. No need to add
nesting for this particular lib.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

setup.py

@@ -10,7 +10,6 @@ setup(name='avocado',
       url='http://autotest.github.com',
       packages=['avocado',
                 'avocado.cli',
-                'avocado.conf',
                 'avocado.core',
                 'avocado.linux',
                 'avocado.utils',