set_version_to.py adaption for Cygwin

Author: gerhardol

.gitattributes

@@ -5,3 +5,4 @@
 *.cs text diff=csharp
 *.sln text eol=crlf
 *.sh text eol=lf
+*.py text eol=lf

Setup/set_version_to.py

@@ -1,3 +1,9 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""Update version in GitExtension source files
+"""
+
 import argparse, sys
 import re