Left TODO:

 * Find initial theme, and if it's a custom metatheme keep it around to put
   in the list when selecting a different theme.

 * Change custom theme removal addition to handle above.

 * Change custom theme text to indicate what themes are being used.

 * Notice when a directory is removed.

 * Sanity check saving.  In particular, \n needs escaping.

 * Fix when saving a theme.  Seems to be a small race condition there
   that screws a lot up.  Should be trackable, though I fear it's going
   to test my fam-fu

 * Fix the collation of the Details dialog.  Seems to be going on theme
   name, not readable name.