Updated AppImage

[Jean-Baptiste Mardelle]

Hi all,

I have just uploaded the latest development AppImage at:
https://files.kde.org/kdenlive/unstable/kdenlive-18.08-beta0.AppImage.mirrorlist

I switched the name to 18.08beta to reflect our last café's decision.
This image should fix all issues reported in phabricator at:
https://phabricator.kde.org/T7082


It also contains 2 changes not yet commited to git: boiko's work fixing 
multiple clip drag from project bin, and my reintroduction of the 
rotoscoping effect.

One known issue is that if you cut a split clip (audio/video), the cutted 
parts don't retain the "split" property so applying speed effect won't work 
on audio after a cut but that will be solved in a later update.

Please test and report problems on phabricator.

Regards
jb