Blender Git Loki

Fix rotate 3D view segment fault

The context was wrong for new modes

Fix T52176: Bevel doesn't correctly work with default empty Vgroup.

`defvert_array_find_weight_safe()` was confusing 'invalid vgroup' and
'valid but totally empty vgroup' cases.

Note that this also affected at least ShrinkWrap and SimpleDeform
modifiers.

WIP: more work in cache

PyAPI: Store PyInstances for ID's

This means once an ID is created,
it will keep using the same PyObject instance.

This has some advantages:
- Avoids unnecessary re-creation of instances on UI poll / redraw.
- Accessing free'd ID's gives an exception instead of crashing.
(long standing annoyance!, though this only applies to ID's
and not yet other data that uses the ID's - vertices for eg).
- Allows using instance comparison (a little faster).

Note that the instances won't be kept between undo.

Topograb: Fixed dyntopo error

Minor fix, crash on smoothness = 100%.

Topograb: Fixed runtime warnings

PyAPI: Fix for instancing (Blender owns a reference)

Also set newly created values to the instance pointer.

Topograb: Fixed cenral vertex error

Cleanup: Remove redundant parameter

Remove CACHE_REUSE

If we use a different area by object, the cache never can be reused

Fix memory leak

WIP: Basic new batch_cache by object

Need more work and review memory leaks

Front and backside of the silhouette are now connected.

Manipulator: only check for highlight once

Was doing 2x lookups which is OK for click-select
but this runs on mouse-move and can become slow.

May enable this again if highlighting logic changes.

Also scale hotspot by pixelsize.

Merge remote-tracking branch 'origin/master' into gsoc2016-improved_extrusion

Curves: Extend and batch extend operators

Renamed "Extend" to "Intersect" and "Batch Extend" to "Extend".

WIP: Add hash for derived frame

This is the first step to allow multi-user datablock

Merge branch 'master' into soc-2017-normal-tools

Changed set_normals_from_faces to respect sharp edges.