#JC-1144 - Added interface for the plugins that can handle http requests
All plugins that implement WebControllerPlugin interface can process
http requests. Plugin generate the html code that will be inserted in the
template ("plugin/plugin.jsp"). Plugin should specify the subPath for
requests it processes. All logic for searching proper plugin for the
request is located in the PluginController class.
Next step: create separate HandlerMapping for the plugin request
handling.
#JC-1144 - Fixed merge for the PluginController class