requires unified dyes commit b0ccff16 or later

side effect:

I added a third shade of the formerly-white checker background
that alternates with the colored overlay.  The colored overlay
follows the standard full Unified Dyes palette.

* Don't trigger global variable warning.
* Change form name to avoid possible bugs in the future.
* Actually (opt-)depend on screwdriver mod.

as a side effect, this also fixes the bug where you couldn't
stack beds to form "bunk" beds.

Place a bed, right-click it with dye to color it.

Place two beds side by side and they'll form a king-size bed, which
you can right right-click with dye to color.

Place a regular bed, then right-click it while wielding another
regular bed (i.e. as if you were trying to place it) and, if there
is room above the first bed, the second will be placed on top and
the bedposts on the bottom one will extend to reach it.  Color
either of the two by right-clicking with dye.

Shift-right-click forces placement of a regular bed without trying
to stack it into bunks.

Right-click while NOT wielding a bed or dye will attempt to let you
sleep (via default beds code).

craft and place an oak shutter first, then right-click it with
dye to color it.  dig to get back the oak + dye.

added recipe that uses cottages:wool, to complement the one that uses
default white wool.

Note that the all-wood kitchen chair cannot be colored.

* Make xgettext not output line numbers
* Remove line numbers from existing catalogs.
* Re-add missing localizations.

To maximize the palette, this uses the colorwallmounted param2 style,
which necessitated modifying the models to make wallmounted look like
normal facedir.  This means couches and chairs can now only ever be
placed upright, facing one of N/S/E/W like a couch or chair normally
would, but since the screwdriver was already disabled, it was basically
impossible to rotate them to any other orientation anyway.

Since this is colorwallmounted, it uses the 32-color abridged Unified Dyes
palette.

localized a misc. variable

Side effect:  Now all of Unified Dyes' colors can be applied.

for wallmounted nodes (engine or _game bug), and put it
to use.

in LBM code for glowlights