Blender Git Loki

SPeedup for particle point cache reading

Order of saving and reading particle point cache was totally different which
made newdataadr() falling back to full data block list traversal for every
point cache entry.

This commit makes it so reading code uses the same order of reading structs
and lists ad the writing code. This required to add special version of list
linking which is capable of running a callback after linking a list element.
This seems to be more robust approach than splitting writing code into
several loops.