Add automatic placement/orientation of double doors.  Place a door, then
a second of the same kind to its right and the second becomes
right-facing.

Made all doors place the left-facing one by default (even if the one you
are placing says it is right-facing, e.g. for leftover inventory).

Hold 'sneak' (Shift) while you place any door to force it to ignore its
neighbors and become right-facing.

Got rid of obsolete left-/right-facing conversion crafts.