Dropdown pixel perfect 🎉

Closes #14333, #14331, #14472, #14515 

See merge request !3337

Documentation: SCSS Style Guide fixes

Fixed a typo and added a section on ignoring issues.

[ci skip]

See merge request !3263

Fix a typo and add a section on ignoring issues.

[ci skip]

Crop avatars on the client before upload

<img src="/uploads/535d69956cc5904870ae5d95132a35af/Screen_Shot_2016-03-17_at_9.55.56_AM.png" width="700">

closes #7959
closes #600 

See merge request !3270

Issue sidebar overlaps on tablet

Closes #14180

![Screen_Shot_2016-03-18_at_13.10.53](/uploads/d1e81778740a034aa98c881a70e55254/Screen_Shot_2016-03-18_at_13.10.53.png)

See merge request !3299

Multi-update issues tests

There were no tests for updating multiple issues at a time - this fixes
that 👍 

See merge request !3357

Fix missing tooltip in project title

closes #14516 

![tooltip](/uploads/121cc3676f4f32044e158cf5f3df5be5/tooltip.gif)

See merge request !3351

Add special cases for built-in Rails routes in development



See merge request !3369

Fixed error with applications delete anonymous token form

Closes #14509 

See merge request !3362

Moved the scss out of a mixin as it was really confusing the hell out of the CSS

Strip commit title when creating revert commit.

Fixes #14453 

See merge request !3352

Fix Milestone.upcoming

The order wasn't happening because of `default_scope`. Blegh.

See merge request !3364

Dropdown alignment

Hopefully the JS will stop this happening in future as well!

Closes #14386 

![Screen_Shot_2016-03-18_at_12.54.32](/uploads/d11b51d3577df3a19b8b3a0fd7b69788/Screen_Shot_2016-03-18_at_12.54.32.png)

See merge request !3298

[ci skip]

Add description of technical debt label in docs

Description for a technical debt label and workflow, as discussed in https://dev.gitlab.org/gitlab/organization/issues/714.

See merge request !3265

Closes #14509

Make sure we get only two returns

@DouweM The other change I made which has nothing to do with Gitlab::Email::Receiver

See merge request !3360

Avoid using the same name between methods and variables

@DouweM This is the one with renaming.

See merge request !3359

Preserve time notes has been updated at when moving issue

Closes #14490

See merge request !3356

Fix build dependencies, when the dependency is a string

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/14485

See merge request !3344

Fix an issue causing the Dashboard/Milestones page to be blank

Fixes #14505 and #14514.

See merge request !3348