New directory for fasteners (will move fasteners out of hardware)
* Removed older metric_fasteners-0.1.scad and thread.scad
* Added fasteners/threads.scad from http://dkprojects.net/openscad-threads/threads.scad
general/constants.scad: comment out echo statement
general/math.scad: incorporate transformations.scad
regular_shapes-0.1.scad: obsoleted by regular_shapes.scad
shapes.scad: incorporate unregular_shapres.scad
transformations.scad: deleted
unregular_shapes.scad: deleted