Color-theme adapting Kdenlive Breeze Icons

[Harald Albrecht]

Hi,

I've made some progress in converting Kdenlive icons into color 
theme-adaptive icons. At this time, I'm keeping this completely 
separate, so some dev may want to pick it up and integrate with the 
Kdenlive source git repo.

Reasons for keeping this separate at this time are: as the Kdenlive 
installation currently is, it does not work properly for icons installed 
into a local ($HOME) subfolder. From Farid's screenshots I can see that 
he also got some wrong Kdenlive Breeze icons due to the way KF5 handles 
themed icon loading. A clear indication that something is wrong is when 
a muted track shows up with the loudspeaker icon with a big red minus. 
When correctly installed, it should be a crossed-out loutspeaker instead.

I've also updated the design of some icons I originally drew and which I 
consider to not really be clear in their current design. In particular, 
the edit (clip) duration icon, as well as the timeline render start/stop 
icons.

Also, I've added some new icons that aren't used yet, but which I would 
like to see getting picked up by the devs. For instance, the 
timeline-clip-in-project icon at this time.

So here's my git repo: https://github.com/TheDiveO/kdenlive-breeze-icons

Enjoy!

Best regards,
Harald