More exact documentation and small fix

extras/contrib/bootstrap

@@ -24,8 +24,8 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 # ***************************************************************************
 
-if test "$#" -gt "2"; then
-  echo "Usage: $0 <host> [distro]" >&2
+if test "$#" -gt "2" -o $1 = "-h" -o $1 = "--help" ; then
+  echo "Usage: $0 [host [distro]]" >&2
   echo "  Prepare config.mak and distro.mak file." >&2
   exit 1
 fi
@@ -36,7 +36,7 @@ set -e
 set -x
 
 BUILD=`gcc -dumpmachine`
-if test "$#" = "1"; then
+if test "$#" -ge "1"; then
   HOST="$1"
 else
   HOST="$BUILD"