Initial changes to allow users to select the default layout of a room

A space admin can have the rights to change the default layout of the room associated to this space. To do that was created a new page in space admin options tab to let admins control the room options.

Refs #960
Created a new way to allow users to select the default layout of a room

Before this modification was impossible to change the layout of a room, all rooms were presented with the same default layout. Now the idea is to let owners/admins choose from a pre selected list of layouts. For do this was inserted in the configuration pages  of the room (space and user rooms) a new field who owners/admins can select the default layout to be used.

Fix #960
Adjustments to set the layout of a room, functional now

Updated bigbluebutton_rails and bigbluebutton-api-ruby to version that now
have it working.
Made small adjustments in the views where the default layout is set in a room.

refs #960
Update bigbluebutton_rails and fix tests

#960 should be done now. Tests are all passing.

refs #960
Merge pull request #13 from mconf/960-default-layout

Conflicts:
	config/locales/en/_simple_form.yml
	config/locales/pt-br/_simple_form.yml
Add .bundle/ to .gitignore