Fix #45: add support for rlimit per service/run/task/inetd/tty

This patch extends the existing rlimit implementation to support setting
limits per service, run/task, inetd, and tty.

Use rlimit in /etc/finit.conf to change the global setting, which is
then inherited to each /etc/finit.d/*.conf.  For each .conf file the
rlimit is reinitialized to the global finit.conf settings.

Also, add `unlimited` keyword, to replace the now deprecated `infinity`
keyword.  The latter is however kept, for compatibility with previous
releases, for the foreseeable future.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/conf.h

@@ -26,6 +26,11 @@
 
 #include "svc.h"
 
+extern struct rlimit global_rlimit[];
+
+int   str2rlim(char *str);
+char *rlim2str(int rlim);
+
 void conf_parse_cmdline   (void);
 int  conf_parse_runlevels (char *runlevels);
 void conf_parse_cond      (svc_t *svc, char *cond);