preliminary privlege escalation unification + pbrun

- become constants inherit existing sudo/su ones
- become command line options, marked sudo/su as deprecated and moved sudo/su passwords to runas group
- changed method signatures as privlege escalation is collapsed to become
- added tests for su and become, diabled su for lack of support in local.py
- updated playbook,play and task objects to become
- added become to runner
- added whoami test for become/sudo/su
- added home override dir for plugins
- removed useless method from ask pass
- forced become pass to always be string also uses to_bytes
- fixed fakerunner for tests
- corrected reference in synchronize action plugin
- added pfexec (needs testing)
- removed unused sudo/su in runner init
- removed deprecated info
- updated pe tests to allow to run under sudo and not need root
- normalized become options into a funciton to avoid duplication and inconsistencies
- pushed suppored list to connection classs property
- updated all connection plugins to latest 'become' pe

- includes fixes from feedback (including typos)
- added draft docs
- stub of become_exe, leaving for future v2 fixes

test/units/TestUtils.py

@@ -498,7 +498,7 @@ class TestUtils(unittest.TestCase):
         self.assertEqual(len(cmd), 3)
         self.assertTrue('-u root' in cmd[0])
         self.assertTrue('-p "[sudo via ansible, key=' in cmd[0] and cmd[1].startswith('[sudo via ansible, key'))
-        self.assertTrue('echo SUDO-SUCCESS-' in cmd[0] and cmd[2].startswith('SUDO-SUCCESS-'))
+        self.assertTrue('echo BECOME-SUCCESS-' in cmd[0] and cmd[2].startswith('BECOME-SUCCESS-'))
         self.assertTrue('sudo -k' in cmd[0])
 
     def test_make_su_cmd(self):
@@ -506,7 +506,7 @@ class TestUtils(unittest.TestCase):
         self.assertTrue(isinstance(cmd, tuple))
         self.assertEqual(len(cmd), 3)
         self.assertTrue('root -c "/bin/sh' in cmd[0] or ' root -c /bin/sh' in cmd[0])
-        self.assertTrue('echo SUDO-SUCCESS-' in cmd[0] and cmd[2].startswith('SUDO-SUCCESS-'))
+        self.assertTrue('echo BECOME-SUCCESS-' in cmd[0] and cmd[2].startswith('BECOME-SUCCESS-'))
 
     def test_to_unicode(self):
         uni = ansible.utils.unicode.to_unicode(u'ansible')