Adding tag backend

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Adding TagView for managing tags

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
It is not a backbone view

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Transform Middleware for auto insert

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Applying auto insert to playlists

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Saving transform id on reverse relation

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Test tags fetch

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Adding search to tags

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