Log Message:
Fix setrlimit(3): Invalid argument

The new code that unlimits many resources appears to have been problematic
on a number of fronts. Fetched the current version of src/limits.c from
the sudo hg repo. RLIMIT_STACK (i.e. "3") is no longer set to \ 
RLIM_INFINITY.

Added code to output the name of the limit instead of its number.