Waf build system

This PR is more of an idea and a proof of concept and not ready to be merged.

The suggestion is to replace Factors build system based on batch and shell scripts with waf: https://code.google.com/p/waf/ waf is a "real buildsystem" like autotools and both much faster and easier to maintain than hand-coded makefiles and scripts. The difference becomes more apparent when you add advanced build features, like making distribution tarballs, automated test running, window installer and installation targets. It's really hard writing all that by hand. Currently the wscript I've written only builds and installs, but I plan to add more features to it.

waf only requires Python and has is included in the pr. So when you have applied it, you can build using:

    python waf.py --prefix=/blah configure
    python waf.py build
    sudo python waf.py install