* fixed/ overhauld asset & blueprint scanning
* added polling for blueprints (not 100% sure yet)
* add-on-prefs => settings
* removed the now obsolete auto-export operator & preperences
* a lot of other minor changes
* added correct injection of assets + export path to blueprints
* moved a few common elements to "core" for better reuse
* more tweaks/ experiments with paths handling
* moved & overhauled a few of the blueprint & assets tools
* lots of minor tweaks & changes