version using only the dbfpy library, plus some other minor changes. test for speed against hybrid version
Merge branch 'dbfpy-only' of https://github.com/dogtato/dbfutil

Conflicts:
	README.md
	dbfutil.py
very early work in progress, in no way functioning or even properly designed
mostly converted, apart from the main join function
Very initial conversion is complete, now doing initial debugging
Conversion complete, seems to be working properly. Haven't run a full test yet.
final commit before merging back to start on pygtk. Field calculations aren't really implemented