Blender Git Loki

Fix crash when ending VR session through "Toggle VR Session"

Fix memory leak when closing Blender with running VR session

Fix various space transform issues

Add positional tracking option (3DoF vs. 6DoF)

For passing around the HMD or preparing scenes for 3DoF interaction
(e.g. cardboards) this option is quite handy.

After feedback from @sebastian_k and @noemis, decision was that
disabling the positional tracking should not reset the position to the
starting one. It should just keep whatever is the current position.
So we have to get the local pose (which is different from the per eye
pose) out of OpenXR so we can have more dynamic base position that
changes depending on the positional tracking option.

Not that this isn't working 100% as wanted: There's a slight offset when
disabling the positional tracking. I don't want to spend too much time
on something minor-ish while there are more major features to get done.

Color transforms were fixed in Windows MR -> disable our workaround

SDK changed loader lib name on Windows, update for that

Merge branch 'master' into soc-2019-openxr

Merge branch 'temp-openxr-ghostxr' into temp-openxr-blenderside

Merge branch 'temp-openxr-directx' into temp-openxr-ghostxr

Merge branch 'temp-openxr-buildstuff' into temp-openxr-directx

Merge branch 'master' into temp-openxr-buildstuff

Remove files to sync with latest changes in patches

Merge branch 'temp-openxr-blenderside' into soc-2019-openxr

Merge branch 'temp-openxr-ghostxr' into temp-openxr-blenderside

Merge branch 'temp-openxr-directx' into temp-openxr-ghostxr

Merge branch 'temp-openxr-buildstuff' into temp-openxr-directx

Merge branch 'master' into temp-openxr-buildstuff

Update branch to include changes from split off patches

Bring back utility batch and config file for Oculus support

Merge branch 'master' into soc-2019-openxr