[mod] PaintBG (EE) portrait pack

In cooperation with @LavaDelVortel we revived the PaintBG portrait pack by Artastrophe for use in Enhanced Editions. Well, by revived I mean I was preparing another portrait pack and offered to grant the code for the use in PaintBG, which I use myself, but which required manual file copying like in the ol' days. This means the code is brand new and has brand new bugs! It also means that some installation options may seem a bit of an overkill, as it was designed for a larger portrait set. The portraits are still the same, except it also includes newer portraits which Artastrophe published since last official release. You can download the confidencence inspiring version 0.0.1-beta temporarily from github:

Windows
Mac
Version for linux will have to wait until I have access to a Linux machine and more time (or someone willing to help with getting static graphicsmagick).

The mod will return to SHStudios once 1) the latter s up; 2) the former leaves the beta stage - I don't have permissions to upload there but need a way to squash bugs. Please let me know if it works on Mac and Linux - I haven't tested it but use platform-dependent GraphicsMagick binary to convert jpg to bmp. Also, I have no idea if it works with EET, but unless it does something special portrait files, it should - and I intend to support it given beta testers.