* find_directory() and hard-coded paths use /boot/system instead of
/boot/common.
* The build system creates the writable directories in /boot/system
instead of /boot/common.
* The build system no longer installs any packages in /boot/common.
* Deskbar now uses ~/config/settings/deskbar/menu_entries for its menu,
falling back to /system/data/deskbar/menu_entries, when the former
doesn't exist. The latter always exists and is a virtual directory
merging the deskbar/menu subdirectories of ~/config/settings/ and
<any installation location>/data/. So, if a package provides a
deskbar menu symlink, it is added automatically when the package is
activated. The user can add own menu items by putting stuff into
~/config/settings/deskbar/menu/, only use their own organization by
symlinking it to menu_entries, or do fun stuff by making menu_entries
a customized virtual directory.
* HaikuImage: No longer create any deskbar menu symlinks in the user's
settings directory. Instead add them to the Haiku package.
* OptionalPackages: At least for the optional packages that do have
hpkgs, no longer create deskbar menu symlinks in the user's settings
directory.
* Move all Deskbar settings files to ~/config/settings/deskbar/ and
drop the "Deskbar_" prefix.