Also fixed a bug in ssh.py where an attribute was being inappropriately
initialized in the _connect() method instead of __init__()

* PluginLoader class will now be more selective about loading some
  plugin classes, if a required base class is specified (used to avoid
  loading v1 plugins that have changed significantly in their apis)
* Added ability for the connection info class to read values from a
  given hosts variables, to support "magic" variables
* Added some more magic variables to the VariableManager output
* Fixed a bug in the ActionBase class, where the module configuration
  code was not correctly handling unicode

v2_final Testing additions and fixes

* Fix import pathing for units.mock
* Add some additional requirements
* Use compileall to test compatiblity with different python versions

Fixes #10945

Add ability to specify using ssh_args in synchronize for v2

Fixes #10923

Conflicts:
	lib/ansible/modules/core
	v2/ansible/modules/core
	v2/ansible/modules/extras

fixes #10891