[rst mode] Rewrote from scratch

The old mode was not supporting many rST constructs, or not in
sufficient detail. Features/changes:

 * no `backUp` ops to keep things fast;
 * kept `python` inner mode integration;
 * added `latex` inner mode;
 * eliminated `verbatim` configuration parameter;
 * eliminated non-standard tokens: the old mode was producing `footnote`
   and `citation` tokens, which were replaced with `quote`;
 * many more details: visually compare highlighting between old and new
   to get an impression;
 * MIT license (copied and adapted form `python` mode);
Allow modes to specify their own flattenSpans option

And use the editor-wide option when no value is found on the mode.

Issue #1281
Rename Zen Coding to Emmet in real-world uses

+ add CodeMirror Movie link
[show-hint addon] Close pop-up when punctuation is typed
Fix scrolling of pageup/pagedown, make them move a little less than a screen

Closes #1290
[markdown] Improve highlighting of lists.

Also includes improved support of nested lists.

Closes #1276.
[markdown] Fix test that was changed in a2ad87f27d021a95f661ac9b106e1f79c6c86a1a.
[markdown] Improve highlighting of blockquotes.

Add support for nesting and avoid hiding code highlighting.

Related to #1276 (but blockquotes, instead of lists).
[markdown] Remove `emstrong` entirely.

Should use `em` or `strong` instead.
[markdown] Only match list items that follow a blank line.

Per Dingus.
Hack to work around Safari crash on setDragImage

Closes #1284
Replace Verilog demo code with something that's not GPL-ed

Closes #1292
Try to make page-up + page-down place the cursor back in its old place

Closes #1291
Add leaveSubmitMethodAlone option to disable form submit hack
[gfm] Add support for task lists.

Closes #1165.
[markdown] Fix list highlighting.

Previously, lists following other content weren't always highlighted.
Mode tcl added.
Added mirc mode.
[mirc mode] Integrate.
[tcl mode] Integrate