Adds filter hook version in for release start

Also adds sample script.

Signed-off-by: Peter van der Does <peter@avirtualhome.com>

git-flow-release

@@ -153,6 +153,10 @@ cmd_start() {
 	DEFINE_boolean fetch false "fetch from $ORIGIN before performing finish" F
 	parse_args "$@"
 	BASE=${2:-$DEVELOP_BRANCH}
+	# Run filter on the version
+	VERSION=`run_filter_hook release-start-version $VERSION`
+	# As VERSION might have changed reset BRANCH with new VERSION
+	BRANCH=$PREFIX$VERSION
 	require_version_arg
 	require_base_is_on_develop
 	require_no_existing_release_branches

hooks/filter-flow-release-start-version

@@ -0,0 +1,14 @@
+#!/bin/sh
+#
+# Runs during git flow release start
+#
+# Positional arguments:
+# $1    Version
+#
+VERSION=$1
+
+# Implement your script here.
+
+# Return the VERSION
+echo ${VERSION}
+exit 0