Created OOPPluginManager and the OOPClientPlugin and OOPServerPlugin

The OOPPluginManager is inherited from PluginManager to ensure the
side-by-side compatibality of in-process and out of process plugins.
Also, since the plugins are going to be out of process, the
OOPClientPlugin and OOPServerPlugin are going to act as d-bus interface
interaction instances to deal with the plugin processes. Next, the
methods in PluginManager have to be implemented to start process plugins

Signed-off-by: Sateesh Kavuri <sateesh.kavuri@gmail.com>