Move license files to license subfolder

For the final builds instead of leaving all the license files in the main
folder, we move them to a "license" folder.

Also, adding more licenses here (MIT, Apache, ...).

Differential Revision: https://developer.blender.org/D8999

Fix T66614: Text objects: Truncate overflow for non-top aligned text

Cleanup: Remove warning re: const qualifier discarded

Warning introduced on a5db981b0ea044313239c3cc2ee92d.

Fix T76346: Moving objects in outliner doesn't update local collections

The fix involves going over ALL the possible combinations of viewlayers
and viewports and re-sync.
I tested this with multiple windows, multiple scenes and multiple
viewlayers.

Since (for now?) the operation of syncing the local layer collections is
not too expensive, this is not so bad. In theory we could improve this
by checking if the collection the object was moved to and from is in the
scene before iterating over it. I don't think it is worthy though.

Thanks Arun Parolikkal for the initial attempt on D8342.
Final patch reviewed by Brecht Van Lommel.

CMake: Force experimental features to be on/off based on release cycle

This makes it error-proof to disable/enable experimental features
during the release cycles. Since it is handled by CMake it should always
work reliably now (not depending on someone turning this on and off).

Reviewed by Sergey Sharybin.

Linux: 2.90 release information in appdata

Doversion: move (fix) 2.80 checks to 2.90

Some doversion checks were done in the wrong file, meaning they could potentially
be running in the wrong order if they require another fix to run prior to them.

This is technically is a cleanup. And technically a fixup for
9e0a4fcaad1f.

Blender 2.90 subversion bump

Preparing for release.

Splash: new image for 2.90 by Daniel Bystedt

Linux: 2.90 release information in appdata