Plugin framework improvements
Now it's possible to generate plugin for platform from any model, so that it's possible to create a non-language plugin for MPS. This will allow to create "standalone" plugins, which will not require the presence of plugin's module for the plugin to work (e.g. a VCS plugin).
Note: Icons in actions don't work properly in non-language plugins for now.
In addition, plugin components are no more created via reflection. This can will improve reloading performance of large plugins.