Reworking README

[dennisguse]

The current README contains only limited information especially considering new people interested in the SSR.

I believe it would be great to add:

• Brief description of the SSR (Goal, Features, Limits)
• Basic information (Website, Mailing list, Wiki, License)
• Supported platforms (MACOS, Linux, PD?)
• How to compile the SSR on some basic platforms NOTE: I know the INSTALL contains some information, but that is rather hard to read.

In addition, I would remove the (c) as it is not really something important for users/developers and either remove it or move it to a different place.

Also, I would prefer to use Markdown instead of plain/reStructuredText.

What do you think?

[chohner]

Some information on how to compile is in operation.rst. This pull request contains a commit that expands a bit on the steps required on OSX - Probably still not a bad idea to refactor this