Revert 60358, it made irregularly scaled objects behave incorrectly, checking out different approach here.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@60513 954f8c5b-7b00-dc11-b283-0030488c597c
Fix an own regression introduced in the dyntopo cleanup commits. Do not
remove a vertex from the pbvh if the only face it was part of was
removed from the pbvh. This should work but no time to investigate now
properly, and better have a solid release. The problem could be seen
when sculpting to open meshes. Some vertices and faces on the boundaries
would become stuck and unresponsive.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@60514 954f8c5b-7b00-dc11-b283-0030488c597c
real fix for #36695, scale brush stroke with maximum scale component,
except layer brush where the previous algorithm is used.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@60515 954f8c5b-7b00-dc11-b283-0030488c597c
adjustments to sculpt cache scaling code, (float/double promotion)


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@60516 954f8c5b-7b00-dc11-b283-0030488c597c
Merge branch 'master' into tri_modifier