Added recent activity to spaces with new gem
Activities for posts and corrections to posts views
Using spaces as owners of activities
Corrections to events and using recent_activity
Recent activity for news and simplifying views and controllers
Refactor news views
Remove residual javascript and css from attachments
Pretty text for recent activity
Treating cases when recent activity tracked object's been deleted
Merge remote-tracking branch 'origin/public_activity' into branch-v2

refs #906

Conflicts:
	Gemfile
	app/assets/stylesheets/app/attachments/index.css.scss
	app/helpers/icons_helper.rb
	app/views/news/show.html.erb
	app/views/posts/_post_with_children.html.haml
Update db schema after merging "public_activity", refs #906
Change the indentation in a couple of files to 2 spaces, refs #906
A bit of refactoring in private messages

Removed old views and a few other parts of code that are not being used anymore.