all: Bump ABI/API version

Signed-off-by: Jens Georg <mail@jensge.org>
Update .gitignore
renderer: Allow the controller to expose its play mode

Currently the play mode is hardcoded into the AV transport. Since
we now support external controllers it makes sense to let them
own the play mode since they own the playlist. This patch moves
the playmode to the controller.

Signed-off-by: Richard Röjfors <richard.rojfors@gmail.com>

https://bugzilla.gnome.org/show_bug.cgi?id=737513
renderer: Implement SetPlayMode

Add an implementation of SetPlayMode, a method is added on the
player controller interface to validate if the new play mode is
valid or not. If it is the play_mode property of the controller
gets the new mode assigned.

Signed-off-by: Richard Röjfors <richard.rojfors@gmail.com>

https://bugzilla.gnome.org/show_bug.cgi?id=737522