[searchcursor addon] Remove forgotten debugger statements
Correct a typo in manual.html
Add mark-selection addon and demo page
Clean up mark-selection add-on
[match-highlighter addon] Rewrite to use defineOption and an overlay
[match-highlighter addon] Update documentation
Repair context menu on IE9
Use a Pos constructor instead of repeating {line, ch} literals

This helps performance on v8 (in microbenchmarks) and is less noisy.

Regular literals are still accepted, the constructor is only used to create
objects, doesn't attach any methods.
[show-hint addon] Support PageUp/PageDown/Home/End keys when dialog is active
[show-hint addon] Don't close hinter when typing first letter of word
Roll up the active-line addon!
Fix some issues on mark-selection

 - When mark-selection is deactivated the mark was not removed.
 - When mark-selection is [re]activated it immediately calls
   updateSelectedText() to set the mark if there's already a selection.
 - In addition to removing the mark, the handle is completely deleted
   to leave the CodeMirror instance in a clean state, and avoid re-deleting
   the mark if it's activated again.
Talk about mark-selection and active-line on the manual.
Add a bi-directional text demo

Closes #1180
Sanitize logic that prevents editing in readOnly ranges

It was really quite misguided before.
[show-hint addon] Improve heuristic for keeping or closing the pop-up
[show-hint addon] Remove unused variable
[show-hint addon] More careful positioning of pop-up
[show-hint addon] Close pop-up on blur, make page-up work when near top of list
Wrap undo/redo in an operation