core: Only get max user processes if we have RLIMIT_NPROC

Solaris doesn't, for instance, so this is one step closer to
building our stuff on Solaris.

Signed-off-by: Andreas Ericsson <ae@op5.se>
xsddefault: Only assign xsddefault_temp_file #ifdef NSCORE

This makes the cgi's build properly again.

Signed-off-by: Andreas Ericsson <ae@op5.se>
base/utils.c: Remove code handling escape characters

This patches moves the responsibility for handling escape characters
from the core to worker processes. The exclamation mark is excepted as
it is used as the argument delimiter. Note that any code using the
runcmd functions from libnagios get escape handling for free.

Signed-off-by: Andreas Ericsson <ae@op5.se>