Merge pull request #301 from knowledgepoint-devs/merge1

Fix for fakepath issue https://trello.com/c/ESlli63m/456-fakepath-issue-in-attachments.
used more broad regex for the fakepath issue solution
made change language link to keep user on the same page after switching the language
allowed users to edit moderated posts
applied patch to send email alerts when edit is approved by moderator
added default ask group id to the ask form if the id is not set
allowed moderators to be thread moderators on public threads
Re-apply the change for
https://trello.com/c/JGQ2LjvV/340-editor-of-minor-edit-not-to-show-as-last-person-to-update-a-question-on-main-question-list,
which got dropped somehow, presumably during modal merge, and re-raised
at
https://trello.com/c/zeM2dKQM/473-investigate-possible-issue-with-minor-edit.
Merge remote-tracking branch 'upstream/merge1' into merge1

Conflicts:
	askbot/models/post.py