Blender Git Loki

* removed strength multiplier. the limit on strength is a soft limit, the hard limit is 10
* moved variables used to draw brush from Brush to Sculpt, there only needs to be one copy of these at a time, not one set per brush
* bumped up sub file version number so any files saved can be differentiated from older files. I expect this to be a vert short lived thing as the file version should jump with the upcoming 253 release
* removed 'duplicate brush' button and made the + button duplicate the current brush (or create a new brush if all are deleted)
* changed some defaults for new brushes
* do_versions and init_userdef_do_versions do some sanity checking and set defaults values new in this branch