Summary

Create a handle from one of several (15) profiles generated in Inkscape.
Add grips, a ferrule, holes for hanging, or grub-screwing to a tool.
Also flat faces for hand carving.
Scale or shift the profiles.
Or make new profiles in Inkscape and manually add to the program. (Instructions in the code).

Instructions

Dowload or use the Customizer. Several tabs for overall shape and grips etc.

How to make/load in profiles from Inkscape:
Sample svg included in files.
In Inkscape:

Set document properties to mm and set size to 100mm high x 50mm wide.
Draw right hand side of profile shape. Neck end pointing down.
Make sure first point is at top.
Last point of profile must be directly below the first. Closed or open profile - does not matter.
Exact placement and scale on sheet is not important. (calculated from data)
Export profile using "Paths to OpenSCAD" Extension
-see http://www.thingiverse.com/thing:25036

In the SCAD file:

Open the .scad file and clip out the [[],[],...] region inside polygon() definition.
Paste that list into a new variable(unique name) in the SCAD filet similar to ones included.
Add that variable to the "profiles" list variable (below the list of profiles).
Add the name of the profile to the "Profile_shape" param for the Customiser near start of file.

Customizable Profiled Handle