[kdenlive] New keyframe now in test in git master

[Jean-Baptiste Mardelle]

Hi all,

I just enabled the new keyframe system in git master.
You can try it with the following effects:

* volume
* brightness (keyframable)
* gamma

New features include:

* Keyframes can be of 3 different types:
 - discrete (stairs like), linear(lines) or smooth (curves)
* Keyframes can be attached to clip end:
 - right click on a keyframe in timeline and select attach to end,
   all keyframes after that one will be attached to end, useful for fade 
out
* Presets can be saved for an effect or for all effects
 - it means you can for example save a nice fade in curve to a preset,
   and reload it on another clip's effect

There are still a few rough edges and a few bugs, feedback is welcome.
Also, current git master can be tested for Ubuntu users with our new PPA 
kindly prepared by Vincent:

ppa:kdenlive/kdenlive-master

regards
jb