S7 branch

Hi all,

I just installed Max' S7 branch and it compiles and runs fine.
S7 scheme indeed seems much faster than Guile and I like the idea
that we can simply include the sources into TeXmacs as we do for Hummus.

Are there any important things that I should do to improve the S7 branch?
Of course, I can try to work with it for a while and see how it behaves.
But maybe there were some particular remaining points that I should look into.

I already noted that none of the plug-ins are recognized.  Is that normal?

Best wishes, --Joris