Added -c switch to dracut to use a custom dracut.conf

Also some doc updates.

HACKING

@@ -18,4 +18,3 @@ and set
 
 Requirements:
 * udev
-* nash (for switchroot until we get in util-linux)

TODO

@@ -4,9 +4,6 @@ are/should be marked with "FIXME" in the code
 
 INITRAMFS TODO
 --------------
-* We have a horribly ugly switchroot implementation whose only
-  good point is that it gets rid of our dependency on nash.
-  It needs to be replaced by something nicer.
 * The hard-coded list of udev rules that we care about is kind of
 lame.  See about getting /lib/udev/initrules.d or similar for storing
 the rules that we care about in the initramfs.  These could be

dracut

@@ -15,14 +15,17 @@ while (($# > 0)); do
 	-h|--help) echo "Usage: $0 [-f] <initramfs> <kernel-version>"
 	    exit 1 ;;
 	-v|--verbose) set -x;;
+	-c|--conf) conffile="$2"
 	-l|--local) allowlocal="yes" ;;
 	--allow-missing) : ;;
 	*) break ;;
     esac
     shift
 done
-conffile="/etc/dracut.conf"
-[[ $allowlocal && -f dracut.conf ]] && conffile="dracut.conf"
+[[ -f $conffile ]] || {
+    conffile="/etc/dracut.conf"
+    [[ $allowlocal && -f dracut.conf ]] && conffile="dracut.conf"
+}
 . "$conffile"
 
 [[ $allowlocal && -f dracut-functions ]] && dsrc="." || dsrc=/usr/lib/dracut