[css mode] When indenting, properly pop off prop context before closing brace

Closes #2162
[closetag addon] Allow typing '/' if there's no matching open tag
[scrollpastend plugin] Don't get confused when the editor changes size

Closes #2160
[mdn-like theme] Add
[mdn-like theme] Integrate
[css mode] Added missing animation-fill-mode property

Also resorted the next few lines so one would not stick out farther than
the others.

https://developer.mozilla.org/en-US/docs/Web/CSS/animation-fill-mode
[vim] Fix unescaping of escaped strings for search and replace

Add unit tests.
[css mode] Add simple support for @keyframes

Closes #2161
Bump version number
Wrap all cursors in a div
Move extend and shift flags out of selection objects
Rename confusing variable
Implement multiple selections

Issue #778
Fix selection handling in indentSelection and killLine

Issue #778
Refine and add tests for selection-related deletion commands

Issue #778
Make goLineStart[Smart] and goLineEnd work in multi-selection env

Issue #778
More selection command fixes and tests

Issue #778
Simplify and organize click handling
Implement ctrl-click multi-selection

Issue #778
Implement alt-drag rectangle-selection

Issue #778