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/connection_plugins/fireball.py

@@ -53,6 +53,8 @@ class Connection(object):
         else:
             self.port = port
 
+        self.become_methods_supported=[]
+
     def connect(self):
         ''' activates the connection object '''
 
@@ -64,11 +66,11 @@ class Connection(object):
         socket = self.context.socket(zmq.REQ)
         addr = "tcp://%s:%s" % (self.host, self.port)
         socket.connect(addr)
-        self.socket = socket    
+        self.socket = socket
 
         return self
 
-    def exec_command(self, cmd, tmp_path, sudo_user, sudoable=False, executable='/bin/sh', in_data=None, su_user=None, su=None):
+    def exec_command(self, cmd, tmp_path, become_user, sudoable=False, executable='/bin/sh', in_data=None):
         ''' run a command on the remote host '''
 
         if in_data:
@@ -76,7 +78,7 @@ class Connection(object):
 
         vvv("EXEC COMMAND %s" % cmd)
 
-        if (self.runner.sudo and sudoable) or (self.runner.su and su):
+        if self.runner.become and sudoable:
             raise errors.AnsibleError(
                 "When using fireball, do not specify sudo or su to run your tasks. " +
                 "Instead sudo the fireball action with sudo. " +