create PluginLocator implementation.
simplify NotificationManager to use PluginLocator to find plugins
change plugin location code to use reflection to support multiple extension points in the application
centralise content on html pages.
replaced single quote with double.
added full racesession form to create competition race
separate Monitor.cshtml js into own file.
remove js manual redirection as solved server side redirect (Context.AsRedirect)
add methods to create and stop race session in IDbProvider interface.
implement file upload for pilot pictures. Will upload picture, save into /images/ folder, update pilot profile to take new image, delete the old one, and refresh the edit screen.
