Update bigbluebutton_rails

Included the migration to 1.4.0 as well. Since this version is not done yet,
this migration might change in the future.
Use `description` in recordings to describe them, refs #986

Added migrations to remove the metadata from rooms and to move the content
from the metadata in the recordings to the `description` attribute.
Also added routes and views for the user to edit the description of a
recording when it is made available.

The permission control is ok but not 100%. A few TODOs were added in
Abilities for things that should be reviewed.
Refactoring abilities, remove TODOs for webconfs, refs #986

Some abilities set to web conference resources (rooms and recordings) were
not exactly right, and were allowing more than the user should be allowed.

Now permissions to these resources
Update bigbluebutton_rails, refs #986

Now the redirects when edit editing a recording will work properly.
Also changed the variable names to use `redir_url` (as in BigbluebuttonRails),
for consistency.
Change some paths and actions in MyController for consistency, refs #986

Reviewing the paths for resources of the current user (in MyController).
Now more consistent with what we have for spaces.
Filters attrs normal users can modify in recordings, refs #986

Only admins should be able to edit everything, normal users can only change
the description for now.
Update rspec to 2.14 and related gems that are not used anymore
Add tests for params filtered for rooms and recordings, refs #986

The tests were commented because they needed rspec 2.14 to work. Uncommented
and made them work.