Issue #2976

Closes #2983

See https://developers.google.com/closure/templates/ for documentation.
Closure Templates support text, HTML, JS and CSS code.

I'm not extremely happy with the indentation which is currently based
just on the Soy tags, not on the underlying code. Although this style
is possible and sometimes used, it's not the most common style.

Closes #2658

To prevent race conditions where an API call triggers a
resetInput before the new input has been read.

Closes #2975

The code was confused beyond belief, and the hintWords
functionality will provide the same completion power
without loading an additional addon.

Completing inside a word used to try and take the whole word into
account. This is not typical completion behavior, and often not what
you want. After this change, the addons only take the part of the
word in front of the cursor into account.

Closes #2974

A loop is caused in the Puppet mode when adding a capital letter
due to an incomplete regex match and use of the backUp function.
Resolving this issue required checking for a full match against
the word before calling backUp on the stream.

Issue #2967

Closes #2968

Issue #2969

Issue #2263

Issue #2967

Remove a bunch of convoluting abstractions, make sure the regexps are
actually cached.

This file was taken from
https://github.com/wisenomad/zenburn-lighttable-theme with a few
modifications to make it work in CodeMirror

https://github.com/codemirror/CodeMirror/issues/2915

Issue #2964

Allows convenient showing of panels (DOM nodes) above or
below an editor, automatically shrinking the editor to make
space.

Closes #2960

Issue #2952

Closes #2955

Issue #2928
Issue #2958