Blender Git Loki

Multi-Objects: Select similar armature initial commit

This includes all the modes that don't need multi-object support:

* SIMEDBONE_CHILDREN
* SIMEDBONE_CHILDREN_IMMEDIATE
* SIMEDBONE_SIBLINGS
* SIMEDBONE_GROUP
* SIMEDBONE_SHAPE

Unlike the mesh select similar operator, in this case we take
only the active bone in consideration, not all the selected ones.

I decided not to change that, and keep this 2.79 behaviour.
We could though if we want to.