CodeMirror Release 5.6

[Marijn Haverbeke]

CodeMirror version 5.6 came out today. If you are using the readOnly
option, you might want to upgrade, since 5.5 allowed pasting in
readOnly editors.

* 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 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
* Lines longer than maxHighlightLength are now less likely to mess up
indentation
* New addons: autorefresh for refreshing an editor the first time it
becomes visible, and html-lint for using HTMLHint
* The search addon now recognizes \r and \n in pattern and replacement input

You can see all new patches at
https://github.com/codemirror/CodeMirror/compare/5.5.0...5.6.0
The zip is at http://codemirror.net/codemirror-5.6.zip

If you like CodeMirror and want to support other work I do, take a
look at ProseMirror (http://prosemirror.net), a structured text editor
that I am crowd-funding.

Best,
Marijn