Adding basic documentation for the image_formats feature.
Merge pull request #310 from sixpearls/docs/image_formats

Adding basic documentation for the image_formats feature.
Add unit tests for wagtailcore/whitelist.py
Merge pull request #314 from mope/whitelist-tests

Add unit tests for wagtailcore/whitelist.py
Truncate long search strings

Search query strings must not exceed 255 characters; they will be
truncated if they do. Also added embedly library for Travis.
Merge pull request #316 from mope/313-query-string-crash

Truncate long search strings
all fields now display required asterisk when necessary
Merge remote-tracking branch 'upstream/master'
Doc fix - use https rather than ssh for wagtaildemo clone
Docs fix: Elasticutils 0.9+ is not supported