Modify container API response to better work with ExtJS

* Include container ID.
* Add leaf virtual property.
* Rename "children"  to "data".
* Create minimal ExtJsResponse class to modify response content when necessary.
Add colour property to container entity
Include the sample capacity in the container API response
Add user and container fixtures

* Add hautelook/AliceBundle
* Remove ResearchGroup value object to make fixture generation easier
* Generate fixtures - users are in YAML as they do not have relationships; containers are in PHP as the relationships are a little complicated due to the hierarchy and container/sample container type.
* Modify container colour migration to store hash prefix for hex colour.
Use a small subset of Bootstrap to style the front page

Also includes a possible app icon (a flask) that is displayed on the homepage and used as a favicon (and all the other icon types)
Merge pull request #13 from littlerobot/feature/11-styled-homepage

Use a small subset of Bootstrap to style the front page
Merge remote-tracking branch 'origin/develop' into live-containers
Merge pull request #12 from littlerobot/feature/6-container-database

Use container data stored in database to populate tree view
Merge branch 'develop' into live-containers

Conflicts:
	src/Cscr/SlimsApiBundle/Controller/ContainersController.php
	src/Cscr/SlimsApiBundle/Entity/Container.php
Add colour column, use base rest proxy.