Adding backbone-relational

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Adding new backends and deleting blocbackend

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Moving views to relational models

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Moving destroy pieces to MediaListView

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Order in collections fetching

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Dont let change or delete playlists that was scheduled

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Adding empty options to new backends

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Killing fetch in every view

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
fix loading order for visualsearch and pageable
they interact in a funky way. And now for something a little less broken...
adds readme with module versions
Poiting bb-relational to our fork

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
mediasearch: use pageable method instead of ours, do not fetch if not necessary
PlayoutView: check for null, use newer relational attribute
Timeline: new callback bind and call system.
PlayoutView: correct invocation, scope corrections, avoid using global collections.
Timeline: fetch page when panning.

Details:
 * First implementation
TODO:
 * make it optional
 * make prefetch size configurable
 * fix request interval: wait first
 * callback is failing
Timeline: clear fetch bounds on request success.
Some nothings.
PlayoutView: dedicated collections and server search for Universe.
PlayoutView: adjustments for lazy load of related collections.