just checks for creative mode/priv directly instead, as needed.

Uses "color = <foo>" in the tile image def instead
of compositing with ^[colorize or ^[brighten.  Saves RAM.

There are 3 false positives remaining after this patch, so
the bulk of the issues are fixed now.

fix books and swing's on_place to handle CONTENT_IGNORE and CONTENT_UNKNOWN and to always return their itemstacks

 - Buckets couldn't be used to take default:water_source nor default:lava_source
   because the overwrite made in homdecor/exterior.lua replaced that way of
   working. This patch makes both well and sources work.

since it is derived from minetest's old/"minimal" wood texture.

generic black metal is used for all of these now, colorized.
also, added a bit of noise to the texture.

to bring them all together into one "category" instead of being scattered across the directory
also combine a couple dupes.

called "generic wood".
(gets rid of the redundant copy I added as "old wood")