* Fix bug where you could paste into a `readOnly` editor
* Show a cursor at the drop location when dragging over the editor
* The [Rust mode](http://codemirror.net/mode/rust/index.html) was
  rewritten to handle modern Rust
* The editor and theme CSS was cleaned up. Some selectors are now
  less specific than before
* New theme: [abcdef](http://codemirror.net/demo/theme.html#abcdef)
* Lines longer than [`maxHighlightLength`](http://codemirror.net/doc/manual.html#option_maxHighlightLength)
  are now less likely to mess up indentation
* New addons: [`autorefresh`](http://codemirror.net/doc/manual.html#addon_autorefresh)
  for refreshing an editor the first time it becomes visible, and `html-lint` for using [HTMLHint](http://htmlhint.com/)
* The [`search`](http://codemirror.net/doc/manual.html#addon_search)
  addon now recognizes `\r` and `\n` in pattern and replacement input

Closes #3456

Closes #3457

Should reduce the indentation issues after long lines

Issue #3443

- Provide custom list through CodeMirror hintOptions to kickoff
  autocompletion for domain specific usage.

Since the library is completely oblivious to module loaders

Issue #3447

For example:

body
  color $red

.content
  color #000

The .content was highlighted as the variable-2

Issue #3438

Closes #3417

Issue #3434

Also some general improvements to material.css and solarized.css

Don't treat backslashes specially inside of them

Closes #3428

Issue #3423