Add CKEditor-TeXZilla plugin

Link to CKEditor-TeXZilla: https://github.com/r-gaia-cs/CKEditor-TeXZilla

For this commit it was used c4e484c7f9fd71f5f313892a3da2919ee2b14722
added google-analytics.js with a function that tracks outgoing links
fix bug 976025 - Prevent icon wrap for external links
Merge pull request #2050 from icaaq/issue2048_track_outgoing_links

added google-analytics.js with a function that tracks outgoing links
Merge pull request #2055 from darkwing/976025-external-icon

fix bug 976025 - Prevent icon wrap for external links
Revert 2f62c0ceee7b2745276082b62c111fd57d3d174e

This commit is causing bug 976328. Reverting for now.
Merge pull request #2059 from openjck/revert-ga-outgoing

Revert 2f62c0ceee7b2745276082b62c111fd57d3d174e
Revert cced5a201be5348f1f32cbbdaa61e922cf4b2bdb

Well, it turns out 2f62c0ceee7b2745276082b62c111fd57d3d174e did not
cause the bug after all. I still have no idea why reverting it fixed the
problem on stage, but it seems likely that I arrived at a false positive
in my rush to test and deploy a fix.

And with that, I humbly submit a pull request to revert a revert that
did not cause a problem. //developershame
Update based on version 1.0
Merge pull request #2060 from openjck/revert-revert-ga-outbound

Revert cced5a201be5348f1f32cbbdaa61e922cf4b2bdb
Revert "Issue #1964: DB fields for generated content - quick links, zone nav, and body HTML"

This reverts commit 59557f71f8f8ca166fd80dc26db34c3f83ae2115.
Merge pull request #2063 from groovecoder/revert-content-fields

Revert "Issue #1964: DB fields for generated content - quick links, zone...
Hard restart for httpd in chief_deploy.py
Merge pull request #2065 from lmorchard/hard-restart-for-apache

Hard restart for httpd in chief_deploy.py
Merge pull request #2038 from r-gaia-cs/TeXZilla

Add basic math editing features