Main directory for those seeking to build picogen and the frontend.

to build picogen ...
* aux:         libraries too non-trivial for inclusion in renderer or gui
* renderer:    self-explaining
* gui:         folder for graphical frontends to picogen

additionally those ...
* upstream:    stuff from external sources
* tinkerspace: things (currently) not intended for production 
* tools:       useful things that are not required to build picogen itself


FOLDERS THAT ARE ALL UPPERCASE ARE RESERVED FOR BUILD-OPERATIONS. CHANGES
MADE TO THEM COULD BE OVERRIDEN AND ERADICATED, e.g. "BUILD/"