ppmd install instructions?

[alexsantee]

The default algorithm for compression is ppmd, but I couldn't properly install it. There seems to be no package of it, at least for arch linux. Also, the link for it at http://ctxmodel.net/files/PPMd has no install instructions and I didn't manage to compile a version that works for damicore.

I tried other versions of ppmd but they show an error because they do not recognize the parameters that damicore.py uses. More detailed instructions would help to find what particular implementation was used.