Added lines, fixed issues and typos in Russian translation

Fixes #469
Added tests for hidden icon span.

Fixes #473
[admin] Add missing :scope argument to translations in forums/index, categories/index

Fixes #483
Remove extraneous scope, as mentioned in #483
Added ability to control whether users can delete posts.

Similar to the currently existing ability to control whether users
can edit posts.

Fixed post view, so buttons reflect whether ability exists or not.

Added tests.

Fixes #485
Added topics that need moderation to view.

These were found in the controller, but were not
displayed in this view.  Now they are listed as well.

Created tests.

Fixes #484
fix friendly_id

Fixes #488
Add bootstrap class to edit button to make it consistent with new.html.erb.

Fixes #493
Merge remote-tracking branch 'forem/rails4' into rails4

Conflicts:
	app/controllers/forem/posts_controller.rb