Bugfix [#34283] armature bones losing their roll setting upon translation in
edit mode

My earlier fix for [#33974] (in r.54061) was causing some problems where
manually specified roll values on horizontal or angled bones were getting reset.
This could be nasty as you might not notice the changes for a while (especially
when using stick bones without axes displayed).

I've now put in place a hacky compromise solution which should catch both of
these situations nicely. For z-axis (i.e. vertical) movements, the r.54061 fix
is used, while for everything else (moving or just touch-n-go), the old setting
is used.



git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54651 954f8c5b-7b00-dc11-b283-0030488c597c