Jenkins automated build server for Windows builds

[Mads Elvheim]

First of all, congratulations with the 2.1.3 release! :-)

I just finished setting up a continuous integration server at 
http://guile.mechcore.net:8080/

It periodically polls the origin/stable-2.0 branch every 12 hours, 
builds 32-bit freestanding versions of guile for Windows, and packs it 
up into a distributable zip archive. I have also set up jobs to track 
origin/master as well as the v2.0.9 and v2.0.11 tags, but these are 
currently invoked manually. (The stable tagged commits are only there 
for convenience).

The Guile test suite is run in QEMU under Windows XP Pro 64-bit, and 
failing tests are conveniently displayed on the build pages.

If someone here would benefit from having privileges to invoke manual 
builds, set up new branches to track or have access to the Windows tests 
server via ssh, I'd be happy to arrange that.

Outstanding issues with my setup which I'm looking into:

* The test suite does not work out of the box on Windows; that is, some 
unit tests gives an exception which makes the test suite terminate 
prematurely instead of returning the test case as an "error".
* In order to get Jenkins to display the test suite results nicely, I 
had to hack together a script which converted the test suite log into 
the JUnit XML format. It only tracks passes, failures and errors. 
Skipped, unresolved and unsupported unit tests are not yet reflected in 
the web interface or in the total tests count. But the raw test suite 
log is printed as a part of the build log output. For example, 
http://guile.mechcore.net:8080/job/GNU-Guile-stable-2.0-Windows/lastBuild/consoleText
* Looking into getting Windows 64-bit builds of Guile to build 
successfully. I'll be trying out some patches people suggested on #guile

I'd be grateful for any feedback and suggestions for improvements.