saving files should default to $HOME (0.5.1)

To-do "sometime"
overhead view in HUD
bookmarks (bookmark window, if we choose to make it non-modal, should
       save its window settings to a separate gophervrbmwindow file)
implement prefs dialogue
file:// ? (including for bookmarks?)
use pref for the gopher image viewer/web browser instead of hardcoded
use pref for the scaling factor
Reticle and HUD showing selector of object in view centre
Image, gif, sound, etc. shapes should have simple vector art
text pop-in needs to be made relative to screen (farther out for bigger width)