Now it will work on any field inside that form, and it's easier to scope
new behavior, which is what we're adding next!

Moved the positioning of the dropdown to be more aligned with the title

Closes #13219 and #13214

Added dropdown to list all projects on project header

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/4212

When clicking the current project name, it shows a dropdown menu with a list of all projects for that group or user.

When closed:

![Screen_Shot_2016-01-14_at_19.17.44](/uploads/a7258ba388dba238fc2f0468711fc729/Screen_Shot_2016-01-14_at_19.17.44.png)

When open:

![Screen_Shot_2016-01-14_at_19.17.51](/uploads/716533d9eb44b123c5fdff36a4740489/Screen_Shot_2016-01-14_at_19.17.51.png)


cc. @jschatz1

See merge request !2438

First, the autosize library was being too controlling and removed the
`resize` property from any elements to which it was attached, removing
the drag handle.

Second, we detect when the user manually resizes an autosize textarea,
and then remove the autosize behavior from it and increase its
max-height.

This should allow for the best of both worlds.

Closes #12832

- No longer depends on the "hidden checkbox".
- No longer depends on manually storing/restoring the scroll position.
  Instead, we take advantage of jquery.scrollTo.
- Event-based.
- Simplifies the state-based styling.