Adding basic documentation for the image_formats feature.
fix styling of preview button on create page when there are multiple preview modes
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
Merge remote-tracking branch 'upstream/master'