Major refactor to make handling name/path manipulation easier.

Most of this is now in doom_base.py, which stores wad/map/name, exposes them as
properties, and also takes care of most common tasks needed for building
command lines and such.

dcc/text.py

@@ -31,4 +31,4 @@ class Text(dcc.doom_base.WadMap):
 				draw(img)
 				img.trim()
 				img.reset_coords()
-				img.save(filename=dcc.config.TextThumbPath(parsed_args.wad, parsed_args.map, parsed_args.name))
+				img.save(filename=self.text_thumb_path())