Posable Parametric Creeper - modified for mold making

Based on http://www.thingiverse.com/thing:62558, but with following modifications:

- head rotation is configurable
- legs and body overlay is configurable
- reduced to single extrusion only
- code modularized

Have successfully used it with http://www.thingiverse.com/thing:31581.

Note: OpenSCAD sometimes fails with certain orientations. Try again but add/subtract 0.01 degrees to the problematic angle.