Extend REST to populate the application list

[stefanoborini]

With pull request #165 we removed the POST and use a REST request to start and stop containers.
We want to do the same for populating the list of available applications.

This require a few additional magic:

• extend the rest resource to provide all corollary data (icon, description name, etc).
• do some jquery magic to populate the list when document.load is done.

Nothing complex, but would be a nice addition.

[stefanoborini]

Note that this should not touch the rest subpackage (which is in the process of migration to a separate independent package), just the rest resources.