Fixes bugs related to creating Templar() objects on the fly, where
the shared loader objects (serialized to TaskExecutor) aren't used
so information loaded into plugin loaders after forking is lost.
Fixes#11815
added deprecation warning
fixed display.deprecated to make version optional (code already assumed this)
turned warning + 'deprecated' in plugin loader into actual call to deprecated()
* 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