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

lib/ansible/runner/action_plugins/script.py

@@ -113,8 +113,7 @@ class ActionModule(object):
 
         sudoable = True
         # set file permissions, more permissive when the copy is done as a different user
-        if ((self.runner.sudo and self.runner.sudo_user != 'root') or
-                (self.runner.su and self.runner.su_user != 'root')):
+        if self.runner.become and self.runner.become_user != 'root':
             chmod_mode = 'a+rx'
             sudoable = False
         else: