The problem was that all outputs got tagged indiscriminately (esp. hidden render layer sockets), leading to full recalculation every time. This was caused by erroneous tagging of bNodeStacks with hasinput/hasoutput flags. This patch restores the old behaviour of tagging all non-static stacks as input values and all outputs that are connected to some input. Only difference is in node groups, where the hasoutput flag is no longer abused for tagging internal buffers, here the is_copy flag is used instead.
This branch adds mostly organizational improvements to the node system by renaming the node folders and files. A couple of internal features have been added too.
Detailed information can be found on the wiki page:
http://wiki.blender.org/index.php/User:Phonybone/Particles2010
