Excluding the module test utilities (module/lib/test)
Added unit tests for some low hanging fruit:

 * Config - getLastUpdated
 * Docs - getModuleDocumentation & getModules
 * Removed unused ImageUtil.downScale and added tests for ImageUtil.convertToJPG
Added some unit tests for the content storage backends
Enable preview processing on Travis CI
Propagating tests exit code in Grunt
Removed 'excluding pp tests' in README.md
Add a note about etherpad-lite @ 1.2.91 in the README
Added a test that verifies previews can be reprocessed with a revision filter
Try to speed up previews build and reduce failures by:

 * Reduce timeouts
 * Purge all previews queues before each test
 * Installing etherpad package
Removed unused lingering compare code in the content API
PR follow-up

 * Purging all queues before truncating Content CF
 * seconrevision -1 rather than initial + 5
787 - Comment creation responses should include profile picture URLs

This regression was caused because we were using the PrincipalsDAO rather
than the PrincipalsUtil. The Util is responsible for adding signed profile
picture URLs.

It seems like comments and discussion messages are the only places
that are currently taking the user object from the request context and
returning it in the response.
Removed line break
787 follow-up

 * Added custom profile pics
 * Checking profile urls when retrieving messages
 * Added jsdoc
Reverted PrincipalsUtil in the authentication init and using PrincipalsUtil when creating messages
Added the excellent log-range.sh script by @mrvisser

The logs will now also contain a line before and after each containing
the title of the test.

The logs for a particular test can be grepped by doing:
```
./etc/scripts/log-range.sh '<test name>' '<test name>' tests.log
```
Merge branch '787-profile-pic' of https://github.com/simong/Hilary into 787-profile-pic
Extended the profile picture tests for commenting
Requiring MQ in the previews tests
(Release 4.2.1) Bump version
(Release 4.2.1) Remove shrinkwrap
Merge pull request #749 from simong/pp-travis

Enable preview processing on Travis CI