Support variable-width text

Updated from 2011 patch by fjakobs:
https://github.com/ajaxorg/ace/commit/36ebe6c49632f7a2955ce9933a7432f238a389b7

* removes old double-width CJK handling
* replaces monospace assumptions with measurements of actual text
* appears to work for Latin, CJK, Thai, Malayalam in ad-hoc testing
* does NOT fully handle RTL text issues (Hebrew, Arabic)
Added Autodesk Maya MEL
Fixed MEL Syntax Highlighter

Fixed grouping errors. Added mel.mel file to test.
add apache_conf mode
cleanup
use css counter for static highlight gutter
Improved D Language mode
cleanup vbscrip mode
Removed unused code; Added missing keywords; Added defaultToken
add selectOrFindNext commands and disable sublime ctrl-d like behavior of ctrl-arrow
check for valid start state in tokenizer
smoother resizing #1687
rename group to aceCommandGroup to not conflict with cloud9
do not freeze browser when calling fold all second time
misc fixes
allow starting and cancelling mouse capture from outside
do not modify dom from computeLayerConfig
revert change to markup.list
Merge pr/1692 into master
update tests