Misc cleanups and fixes from Bruce:

• don't put \n on error() calls, error adds it already.
• don't prepend "ulimit" on error() calls in miscbltin.c.
• getopt typo on ulimit -p -> -u conversion
• get/setrlimit() calls were not being error checked

ulimit formatting cleanup from me, use same wording as bash on Bruce's
suggestion. Add ulimit arg to output on Joerg's suggestion.