added mkrelease.sh script into utils. gitignore modified accordingly since this script was originally ignored

.gitignore

@@ -7,7 +7,6 @@ redis-benchmark
 redis-check-dump
 redis-check-aof
 doc-tools
-mkrelease.sh
 release
 myredis.conf
 misc/*

utils/mkrelease.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+if [ $# != "1" ]
+then
+    echo "Usage: ./mkrelease.sh <git-ref>"
+    exit 1
+fi
+
+TAG=$1
+TARNAME="redis-${TAG}.tar"
+echo "Generating /tmp/${TARNAME}"
+git archive $TAG --prefix redis-${TAG}/ > /tmp/$TARNAME || exit 1
+echo "Gizipping the archive"
+rm -f /tmp/$TARNAME.gz
+gzip -9 /tmp/$TARNAME