Patch to make Windows build use autotools

[Daniel Atallah]

Folks,

A couple months ago, a patch was submitted to make the autotools stuff
capable of building Pidgin (http://developer.pidgin.im/ticket/12218).

I think it is a reasonable thing to do for uses like that ticket
mentions, but I don't have any plans for this to replace the existing
hand edited mingw Makefiles (mainly because it is a PITA to set up a
working autotools build environment on Windows).

I'd like to get the thoughts and opinions of other folks about committing this.

Thanks,
-D