Blender Git Loki

Asset Browser: Apply a pose before rendering its preview icon

When rendering the preview icon of an Action, apply it to the pose
object first. This ensures that the "Refresh" button of a pose actually
uses that pose.

This splits some functions into two flavours, one that acts on all bones
and one that acts on the selected bones only. Normal use of the pose
library only acts on selected bones, but for the preview the entire pose
from the library is applied, regardless of selection.