This stuff is implemented, probably works, needs more testing:
DONE: sbolint and sbopkglint both: complain if PRGNAM has invalid characters.
DONE: if sbopkglint finds a hardcoded $PKG in /var/lib/pkgtools/scripts/*,
      mention doinst.sh in the error message
DONE: check arch of static libs (like the shared lib checks).
DONE: if package contains any static libs, don't suggest noarch.
DONE: check structure and contents of /usr/share/terminfo.
DONE: /usr/share/pixmaps image check no longer includes subdirs.

Not yet implemented:
TODO: stop checking shared libs for +x and being stripped if they're not
      directly in /lib /lib64 /usr/lib /usr/lib64. too many packages
      trigger this, and it just doesn't matter much.
TODO: figure out if /usr/GNUstep is allowed or not.
TODO: sbopkglint reports bad files in doc dir twice.
TODO: sbopkglint should check for stuff like /usr/lib/lv2 vs. /usr/lib64/lv2,
      according to ARCH. see audio/helm, v0.9.0, BUILD=1
TODO: sbopkglint could complain if the SlackBuild sets SLKCFLAGS
      but there's no native code.

Future test ideas:

- duplicate files, maybe the error message could suggest a "ln -s" command
  to use if the file really does need to appear in multiple dirs.

- fonts. make sure they are what their filename says, and are installed to
  the correct /usr/share/fonts/* or /usr/share/kbd/consolefonts dir.

Other ideas:

When linting multiple packages, print a summary: 100 packages checked,
10 failed, 90 passed. Maybe with percentages too.

Clean up the output. Make it easier to grep.