GNUstep display glitches

[Random832 <random832@fastmail.com>]

I have several issues to report about problems in the NS build of Emacs
under GNUstep, and I'm not sure if I should report them as a single bug
or as one bug for each issue.


Brief summary of the issues

- Terrible font display. When the configured font is not found, it
  defaults to some proportional font whose identity I'm not sure of,
  exacerbated by the more serious issue that its display of proportional
  fonts is abysmal.

- Toolbar problems. The toolbar has no background texture, and turning
  off tool-bar-mode simply does not work properly (with results that
  vary depending on if it's done interactively or in an init file, but
  are terrible in both cases)

- Fringe overlaps scrollbar, along with some other scrollbar rendering
  weirdness. (I think that when the whole document is shown, especially
  given the fact that it _can_ be scrolled down, the scrollbar should
  simply be full rather than "blank")

- No Meta key by default. The "Alt" key on my PC keyboard is interpreted
  as "Command" by the GNUstep library, and so becomes Super. The
  "Windows" key becomes Hyper, and is not configurable from within
  Emacs.