Automated build script for Windows builds

[Mads Elvheim]

I made an hacky shell script to automatically build guile from the git 
repo for Windows.
I have only tested it on Ubuntu 14.04 with MinGW-w64, but it should be 
easy to get working
on multiple systems with some small changes.

Repo on github: https://github.com/Madsy/guile-automatic-build
Win32 binaries people can use: http://www.mechcore.net/files/guile/win32/
In addition to building guile, I made some Windows scripts for starting 
guile
with the correct search paths, and to run the test suite.