mgwport helper script and mgwport

[Thomas Braun]

At [1] you can find a short script which helps mw working with mgwport.

A complete recompile can be invoked with
mp dra
or you can create the source patches and edit them with
mp Ps
or just edit the port file with
mp e
.

I've also forked mgwport to [2] as upstream is basically dead.
I only plan to do minor improvements for getting deterministic builds.

[1]: https://gist.github.com/t-b/7e7af6236e860ca6309a
[2]: https://github.com/t-b/mgwport