add git-interactive-merge script

this script allows "merging branches", but uses the interactive rebase
feature to allow you to (de)select (and modify) commits before merging
taken from
http://stackoverflow.com/questions/449541/how-do-you-merge-selective-files-with-git-merge
written by '1800 INFORMATION' (minor edits by me)

Author: Dieterbe

git-interactive-merge

@@ -0,0 +1,15 @@
+#!/bin/bash
+if [ -z "$1" -o -z "$2" ]
+then
+	echo "usage: $0 <from> <to>" >&2
+	exit 2
+fi
+from=$1
+to=$2
+git checkout $from
+git checkout -b ${from}_tmp
+# drops you in an editor, pick the changes you want
+git rebase -i $to
+git checkout $to
+git pull . ${from}_tmp
+git branch -d ${from}_tmp