Quicklisp installation

[pdo]

Hello Sam,

Thanks for merging #93 so quickly. I've realised now though that my comment about the build passing for me wasn't quite accurate, I'd forgotten about my overriding of the Quicklisp-related code in the Makefile.

The problem for me is that I already have Quicklisp installed (in a nonstandard location) and don't want PVS messing with my configuration, so I commented out all the related code in Makefile.in before running configure. Or rather, I did that on the second go after witnessing the build seeming to hang on my first attempt :-)

So now I'm wondering how this should be done in a more robust way. I think the current way of trying to force an installation of Quicklisp into the user's home directory and then trying to change the user's .sbclrc file is not particularly friendly! Perhaps there should be a local version of Quicklisp only for PVS, or maybe try to detect when a user already has a suitable SBCL/Quicklisp environment setup and so work with that.

I'm new to PVS so don't really understand the history of the project, but if there has been previous discussion on this or thoughts about how to make the build process more self-contained and repeatable then I'm willing to lend a hand, where and when I can, to help with the effort.

Paul