[matchtags addon] Only highlight matching tag, try to be more efficient
Stabilize scroll position when removing widgets

(When they are above visible range, scroll up to correspond for
height reduction.)

Closes #1645
Fix problem in widget-preserving line redraws

Issue #1645
Fix bug in character measurement

Issue #1617
[anyword-hint addon] Add
Add registerHelper/getHelper mechanism

Move hinting functions into it.
[fold addon] Move to registerHelper
[lint addon] Move over to registerHelper
[manual] Fix missing </code> tag
[matchtags addon] Fix inefficiency

Issue #1653
[foldgutter addon] Add
Rename combineRangeFinders to CodeMirror.fold.combine
[match-highlighter addon] Improve showToken option
[midnight theme] fixed syntax error
[xml-fold addon] Add fast-case return to findMatchingTag
Add getModeAt method

Use it to prevent some unneeded state computation.
[markdown] Highlight trailing spaces that affect line breaks
[javascript mode] Don't get confused by empty brackets
[javascript mode] Fix bad indentation below if

Closes #1662
Add another exception to the spanAffectsWrapping hack

And turn the hack off in recent Chrome builds.

Issue #1663