Ability to add search providers from plugins
When I was trying to upgrade Redmine Blogs plugin to 0.9.x Redmine and to implement an activity and a search providers I have found that the search engine (acts_as_searcheable, search_controller) in Redmine has hard-coded list of search providers/types without ability to add a new providers/types.
Thus I found that the activity/event/search subsystems are project dependent. In activity/event I have found workaround, but in search don't.
I have patched acts_as_searchable.rb and search_controller.rb to solve described problem.
Could you review the patch and if it's OK apply it to the core?