Blender Git Loki

Writer for strand data and extension for the new motion state data.

Unlike the particle hair writer this one does not work with the particle
system data but the new Strands data. This will allow successive
manipulations of cached hair data by first storing the initial particle
grooming data ("hair edit"), read this data from the cache into a
Strands instance, then apply hair simulation and write the result back
into a second Strands cache.