1. Added a "dev mode" using bpy.app.debug.  Run Blender in debug (w/ --debug) to expose in development, known buggy functionality, or for testing functionality.
2. Added some functions to check for an active element to make usage more intuitive for users.
3. Continued laying ground work for edge fillets.  This is going to take a while as there is going to be some complex vector math I have to work through (see intersect_line_face to get a feel: that is looking like it will be fairly simple compared to this).