Add new utility and init script swclock that sets the system time based on

the mtime of a file. It saves the shutdown time to this file also.
This is handy for systems without a working RTC chip.
Based on an idea by Michael A. Smith <michael@smith-li.com>.
Fixes Gentoo #272073.

init.d/Makefile

@@ -1,6 +1,6 @@
 DIR=	${INITDIR}
 SRCS=	bootmisc.in fsck.in hostname.in local.in localmount.in netmount.in \
-	network.in root.in savecache.in swap.in sysctl.in urandom.in
+	network.in root.in savecache.in swap.in swclock.in sysctl.in urandom.in
 BIN=	${OBJS}
 
 # Build our old net foo or not