Idea -> Thread model migration
Redirect idea url to thread if it has been migrated.
Removing migrated Ideas from index and Newest Ideas sidebar
Setting status to 'Not an IA idea' will migrate it to General Ramblings.
Add additional columns to idea -> thread migration.

%s/migrated_thread/migrated_to_thread/g
Inflated timestamps aren't populated from DateTime instances.
Force thread comment timestamps = thread timestamp on new thread creation

This will stop migrated IA ideas jumping the discussion queue.
Thread model support for migrating to Idea.
Add IA migrate button to threads - no functionality implemented.
New route to migrate thread to IA.
Link in thread title banner to migrate the thread to IAs.
Only show IA migrate button for General Ramblings forum posts
Filter migrated threads out of thread index
Redirect to Idea if the thread has been migrated to one.
Top level idea comments have no parent_id.
Support HTML content thread migration to Idea

This only works one-way.
Merge branch 'master' into john/idea-to-thread

Conflicts:
	lib/DDGC/Forum.pm
Merge branch 'john/idea-to-thread'