Windows Build system fixes

[Geert Janssens]

On woensdag 23 maart 2011, Derek Atkins wrote:
> Geert Janssens <janssens-geert at telenet.be> writes:
> > I will wait at least until tomorrow before backporting, just to see if
> > tonight's build doesn't reveal bugs in my changes.
> 
> Unfortunately last night's build failed, and it failed pretty quickly.
> If you make further changes today I recommend you fire off a build
> manually to check that it works.
> 
> > Geert
> 
> -derek
Yes, I was already looking into it.

The first problem was that newer mingw packages are distributed in lzma 
compression. Our build scripts don't install lzma tools to extract these. It 
turns out that MSys itself ships lzma starting from version 1.0.11. The build 
server had 1.0.10. I have updated that now.

I'm hitting a problem now while building autotools, but from the errors it 
seems to be a problem of mingw not properly installed. I'm short on time right 
now, but will look at it further later on.

Geert