Fix Fab layer errors in Resistor_THT

Created by: grob6000

Script is updated in https://github.com/pointhi/kicad-footprint-generator/pull/93 Fixes the errors we saw with the Fab text, and model associations. Doesn't perfectly comply with http://kicad-pcb.org/libraries/klc/F5.2/ for super-small components, where putting the secondary fab ref inside the body would result in unreasonably small text size (although down to 0.1mm is allowed, this seems non-sensical to me for THT parts with dimensions c. 2mm: how would somebody use this??). Elected to place the ref where the silkscreen reference goes. Should address #74 (closed). Separate PR for the inductor models (and some checking of course) will be required to fix #76 (closed), but should be possible using same updated script above. The script has made some kind of subtle change to the silkscreen offset relative to the previous footprints. It doesn't seem to be a problem to my eye, and variation is very minor (0.06mm offset, larger shape). Let me know if this should be corrected / does not comply. Image of example fixed footprints: