fatalerror() prints a given string to stdout and exits(5). It
cannot format text, so there was a string temptext used with
sprintf() to format text and pass it to fatalerror().
errx() can format text, and it prints to stderr.
As a bonus, this fixes the linking warnings from use of sprintf().
Merging lai's source with this one is very irritating because
they have different indentation styles. I couldn't find what profile
vegard used for his version, so I used these flags (which should bring
the source close to KNF):
-bap
-br
-ce
-ci4
-cli0
-d0
-di0
-i8
-ip
-l79
-nbc
-ncdb
-ndj
-ei
-nfc1
-nlp
-npcs
-psl
-sc
-sob