add git-build script

git-build.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+ORIGIN_NAME=$(git symbolic-ref HEAD | sed 's!refs\/heads\/!!'| sed 's!build\/!!')
+BUILD_DATE=$(date --utc)
+
+git checkout -B "build/$ORIGIN_NAME"
+git add --all
+git commit -m "build from $BUILD_DATE"