Add installation script

[wegank]

This PR adds an installation script for the RAGlib procedures, so that they become immediately available after libname:="$HOME/libs",libname:.

[mohabsafey]

Initially, I wanted to have RAGlib installed as a maple package (with exported and internal procedures). I am just late on this (mainly because of some devs on msolve and on internal procedures of RAGlib). So, I don't know if this makes sense to merge this PR now, while in a couple of months its content may become obsolete (of course, if you really need it, no problem)

[wegank]

I've made changes to src/rag.mm to make it a Maple package, with only HasRealSolutions and PointsPerComponents exported for the moment.

[mohabsafey]

Many thanks. I slightly reorganized things. Does this look good to you?

[wegank]

It still works on my machine. As for the diff, it looks too large for me to review myself; I've sent it to Codex and it says "I didn’t find a clear algorithmic regression in the code changes themselves.", so I presume it's good.