Fetch asset list

Asset infomation about the assets available for a certain kq is fetched when
the asset view of a knowledge quantum is selected.

Assets are not displayed yet neither it's possible to interact with them.
Display assets for a kq selected
Removed unused Backbone view AssetAvailability
Use a Backbone view to display asset information
feature no-video quantums
Merge pull request #26 from kaleidos/feature-novideo-quantums

feature no-video quantums
Add knowledgeQuantumInstance to AssetAvailability
Fix bug related to retrieve solutions of homeworks and exams
Bugfix when editing units, wrong check of media content id
Update documentation. SAML configuration
More SAML documentation
Added can_be_booked field to AssetAvailabilityResource

As it's not possible to determine if the user is inside the booking period
using javascript, a new field called can_be_booked was added to
AssetAvailabilityResource.

The value of the field depend exclusively of available_from, available_to and
the current date of the server.
Private resources for Asset and AssetAvailability
Display Asset Availability from teacheradmin interface
Edit the asset availability for a kq from teacheradmin interface
Filter assets by KQ
Using 'AS' as label for assets in kq

'AS' is used for displaying the asset availability for a kq
both in teacheradmin as in classroom interface
Improve gravatar url generation

Avoid adding an empty 'default' GET parameter to the src of the
image, it was making Gravatar fail.
Fixed filtering by kq and asset in both AssetAvailability resources
Improve reservations view

- Show slot id for each reservation.
- Remove button is shown aligned to the right, with btn-danger class.