The order of rcfile loading:

1. app_dir/defaults
2. themedir/schemerc
3. schemedir/schemerc
4. themedir/themerc
5. userchoices/oroboroxrc
6. userchoices/keyboardrc

Any colors specified in themedir/themerc will override the current scheme,
so a theme should not set any colors in themerc, except for the textcolors
if (and only if) the titlebar pixmap is NOT schemable.

If the theme is schemable, default colors can either be coded in the
pixmaps or specified in themedir/schemerc. Schemable themes *should* set
default textcolors in themedir/schemerc that looks well with the themes
other default colors. (The default colors will be used when no scheme is
selected.)

The themerc should set full_width_title, title_alignment, button_offset,
button_spacing, and button_layout. button_layout should contain all
buttons that is available in the theme, the user can then disable the
unwanted buttons as she wishes in the Settings GUI.
