Better check on the validity of emails

At this moment it was possible to enter emails like:
mailto:info@example.com. This was causing some issue in the frontend,
since those links became html mailto: links.

Fixes: #3516
Since the git clone code is more efficient now we do not need this warning anymore.
Refactor search autocomplete. Use ajax for source

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'efficient-clone' into 'master'

Efficient Clone

Since https://github.com/gitlabhq/grack/pull/1 this warning is no longer needed I think.
Fix search autocomplete

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Prevent duplicate method names in helpers

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Case-insensetive search autocomplete for projets

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Mention change of search autocomplete in CHANGELOG

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Add website url to user
 Merge branch 'improve/search_autocomplete' into 'master'

Improve: Search autocomplete

* fetch options via ajax
* only show options related to user input
* add limit to amount of options
Merge branch 'add_website_url_to_user' of https://github.com/jeromedalbert/gitlabhq into jeromedalbert-add_website_url_to_user

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Conflicts:
	CHANGELOG
Merge branch 'jeromedalbert-add_website_url_to_user'
Merge pull request #6072 from jvanbaarsen/fix-3516

Better check on the validity of emails