Blender Git Loki

Automate selecting HMD device

This automates setting of HMD device UserPref option a bit, so that it's ready to go without manual adjustments.
We use the last device plugged in on startup (if one is available). On runtime, plugging in a device makes it active if 'None' was previously selected in the UserPref option.
Saving HMD in UserPrefs should also be supported, but can't test.
Also removes EVT_HMD_DEVICENUM_CHANGE and version patch, they're not needed anymore.

Send an event when a HMD was plugged in/out

It's not used for now, will commit separately.

More minor cleanup

Minor cleanup

Fix crash opening UserPrefs on some systems.

Merge branch 'master' into HMD_viewport

Cleanup & fixes in GHOST_OpenHMDManager

Fix crash opening UserPrefs->System with HMD session running, fix OpenHMD context being re-created on each redraw of UserPrefs->System, get rid of m_available (can use m_device NULL check instead), other minor cleanup.

Approximate normals for "true" displacement

Attributes for subdivision

Enable displacement for geometry cache

Add bvh for subpatches

Add geometry cache ; geom bvh

Add geometry cache ; subd

Add geometry cache ; sync

Add geometry cache ; mesh

Add geometry cache ; bvh

Add geometry cache ; geom

Add geometry cache ; geom cache

Add basic OpenSubDiv support

Seperate dice and split for subdivision meshes