1) Convert most formspec elements to use string.format(), when the
result would be more readable, or less messy, or at least makes the line
shorter, assuming it looked like it really needed it to begin with.
2) Convert all long `foo..","..bar..";"..baz..bleh..` types of excessive
string concatenation into tables that then get concated only once, when
their containing functions return the final formspec string.
3) In some places in the code, such tables were already being used, and
were named "formspec", while others were named "fs". I settled on just
one name, "formspec", as it's more readable, if longer.
4) There was a mix of styles of adding items to those tables:
* Some places used line after line of `t[#t + 1] = foo/bar/baz`.
* Others places used the form `t[1] = foo, t[2] = bar, ...`.
* Still others used the form `t[n] = foo, t[n+1] = bar...`,
with `n` being increased or reset every so often.
Most of them should now be of the third form, with a few of the second.
I recreated the original layout as best as practical, but by necessity
there are a few minor positioning changes, since the underlying
hard-wired inventory slots are square now and image positioning is now
scaled by exactly 1.250 in both dimensions (as opposed to roughly 1.25
by 1.16).
Backstage, I also needed to fix the aspect ratios of the various
inventory slot elements. That meant redesigning the single-slot image
from scratch. It was already blurry/grainy and a little ugly, and
trying to alter it would have only made it worse.
The slot image is now exactly 56x56 pixels square, set on a 64x64
canvas, so there's a 4 pixel empty space around the edges. The full
256px .xcf workfile is included in the UI folder.
I've re-tiled all slot/inv images from the new single slot.
I also re-rendered the trash can icon from it since it was blurry and
oddly-sized. I couldn't find the original upstream image, so since
they're free, I used one of my Linux system's icons which happens to
resemble it.
I also removed a couple more improper uses of `background[]` where
`image[]` is more appropriate.
There are tons of minor tweaks throughout the code to re-align
everything, and I had to rewrite a few sections to avoid code
duplication and to allow for a little more flexibility (mainly to make
"lite" mode look right).
In a number of places, background[] is misused to place the
inventory backdrop images. Where appropriate, image[] is used
instead, so that "ui_form_bg.png" actually serves as the one
and only true background image.
In so doing, I was able to remake the bag inventory images,
making them only big as is actually needed to hold 1, 2, or 3
rows of inventory slots.
This, in turn, allows a standardized main inventory image to
occupy the lower part of the window, which allows for
consistent inventory image positioning and sizing from one
page to another.
I also removed ui_misc_form.png. Nothing in UI uses it, and
any external mods that used it can just use the standard
inventory and its background.
Lastly, I reduced the background image to 512x384 px. It was
unnecessarily large before, considering it has no real detail.
The larger inventory images are all 512px wide, and multiples
of 64px in height. Before, they were oddly sized.
