Topics management
remove pg
Category subscription model and migration
Fix model creation for CategorySubscription
Forum new post notification process
Merge branch 'forum' of git://github.com/fuzzie360/coursemology.org into development

Conflicts:
	Gemfile
	Gemfile.lock
	app/controllers/application_controller.rb
	app/models/course.rb
	app/models/training.rb
	app/views/layouts/_footer.html.erb
	app/views/user_mailer/new_enroll_request.html.erb
	config/locales/en.yml
	db/schema.rb
	db/seeds.rb
Add start time of milestone.
Make sure an end date is specified for all milestones.
Allow us to specify that a particular template be rendered.
Remove "Back to Top", fix last milestone scrolling beyond page.
Merge branch 'forum-lessonbin' of github.com:fuzzie360/coursemology.org into forum-lessonbin
Never blindly copy and paste. Seriously.
Merge branch 'forum-lessonbin' of github.com:fuzzie360/coursemology.org into forum-lessonbin
Merge branch 'forum-lessonbin' of git://github.com/fuzzie360/coursemology.org into dev/raymoond_dev

Conflicts:
	Gemfile.lock
Unread post query rewritten
Rewrite .select query for unread in individual post
Merge branch 'forum' of git://github.com/fuzzie360/coursemology.org into dev/raymoond_dev
typo in hidden icon
Save some queries in checking posts read status in a topic
remove pg