Fixes #1082
Related to #439

Initial commit to transition from jobmanager's QtConcurrent model to more flexible and simpler QRunnable

Related to #1001

Related to #973
CCBUG: 423337

Don't rebuild existing audio thumbs for playlist on project opening, display playlist audio thumbs in clip monitor

Related to #798

Related to #102

We now just need to also use this data to generate the bin thumbnail and memory usage should get back to normal
Related to #102

Fixes #746

Fixes #89

Related to #382

* Use uint_8 to store audio thumbs (spare memory)
* Fix disappearing audio thumbs on some zoom levels
* Improve target colors (related to !71)

Some cleanup in audio thumbs. Fix recent regression and bug where audio thumbs were not displayed after extending a clip in timeline
Fixes #252

Always create audio thumbs from original source file, not proxy because proxy clip can have a different audio layout.
Force rebuild audio thumbs on clip reload
Fix zooming with ctrl+wheel over timeline ruler

Fixes #40