Feature/jschatz1/sidebar features
* Changes sidebar width (290px).
* Makes shortcuts for <kbd>j</kbd> and <kbd>k</kbd> keys for next and previous issues.

cc/ @dzaporozhets
See merge request !2734
updates after code review: moved coffee code to appropriate file, updated css to not use js-prefixed selectors
Updated comments and Changelog
Removed duplicate line in changelog
Adds the markdown link at the cursor poisition
When writing a comment and then dropping an image it will correctly add the image markdown link at the cursor position

Tested in Chrome & Firefox and both working fine 👍Fixes#12822
cc. @jschatz1
See merge request !2648
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:

When open:

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
Highlight note code and edit preview
More highlighting fixes! Highlighting wasn't applied all the way for
code in notes, diff notes diffs and diff preview (on the file edit page).
The CSS changes further unify the styling for file-content highlighting,
diff highlighting and note code highlighting.
See merge request !2594
All inputs of type `search` will have the gray background
and search icon centered.
Because the search magnifier is a bg image,
I had to hide it with `[value=""]`.
I added a little javascript to make sure each input always has it's
own value.
Fixes tooltip doesn't duplicate the "me" name.
Checks that "me" is not in the array of names in tooltip

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/7978
See merge request !2454