Navigation improvements

- [x] make explore area as part of dashboard
- [x] move navigation links from top right corner to sidebar
- [x] group navigation items on dashboard
- [x] cleanup UI after such changes
- [ ] fix tests

cc @sytses @JobV

See merge request !1177

Feature/control import options

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

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

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

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

* projects from explore page are available from dashboard
* use dashboard sidebar for both logged in and not users
* move explroe projects under projects tab
* move explore groups under groups tab
* move public snippets under snippets tab
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

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

Improved 2FA warning message about lost codes

Fixes internal issue: https://dev.gitlab.org/gitlab/gitlabhq/issues/2472

The warning message now clearly states that access will be lost of the 2FA recovery codes are not saved.

/cc @sytses @JobV

See merge request !1175

Feature/search for archived projects

Resolves #9285

Added note about backing up recovery codes

Several people have tried to recover their 2FA codes. I think we could be more clear about it in the docs.

This is why I added a section about it at the top, so they read it before enabling them.

https://twitter.com/deathgreps/status/632006221814464512
https://twitter.com/benniemosher/status/633768429313372160

See merge request !1923

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

add CommitNote field expose :created_at

add CommitNote field expose :created_at

Make sure blog post MR has WIP keyword

cc @sytses @rspeicher

See merge request !1172

Fix path traversal in HelpController

Closes #2543

See merge request !1922

Fix infinite loop when SAML was incorrectly configured.

See merge request !1170

Fix gitlab:env:info rake task.

Found doing QA.

See merge request !1169

Clear cache to prevent listing deleted branches after MR removes source branch

Closes #2272

See merge request !1160

disallow irrelevant pages by defaults in robots

capitalize URL in "Home page URL"

Update default robots.txt rules to disallow irrelevant pages that search
engines should not care about. This will still allow important pages
like the files, commit details, merge requests, issues, comments, etc.
to be crawled.