Blender Git Loki

- New script:
Wim Van Hoydonck contributed the famous Knife script (put under Modifiers group) developed by Stefano Selleri and himself (thank to both!)
- Added helper function Blender.sys.makename, updated docs and script ac3d_export to use it (shall update other exporters too):
this function is just a simple helper to format a filename as needed (change extension, strip dirname, it defaults to use G.sce as path).
- Added a test method: Blender.Scene.getScriptlinks(eventName):
just testing, if this path proves useful other functions will be added and made general, for objects, etc.