config -> velocity extruding: wire oneshot.0.width with analog output

added net to analog output so the width of the oneshot can be
easily adjusted with M68 from G-code. Cleaneup of obsolete code in
comments
config -> relocate configuration for velocity extruding

this gives the opportunity to keep the directory clean and
make a README file for explaining how this solution works
Merge pull request #180 from luminize/vel-control-extruding

config -> update and relocating of config files for velocity extruding