ash-builtin ulimit command lacks usage text

[John Spencer]

ulimit --help doesn't work, and all usages of ulimit with invalid stuff 
added just silently exits.

root:/$ ulimit foobar && echo success
success

so there's no way to find out how to use it correctly without googling 
around or looking the syntax up on a box with gnu coreutils.

to see which of the flags are implemented or not is impossible as well, 
unless one RTFS.