Suggestion: non-fatal failed imports

[Bill Baxter]

I was thinking, in my Luigi lib, I was just thinking about adding 
support for Schooner's fonts.  But I don't want to require that in order 
to compile. Ok so I could add yet another version flag, but I was 
thinking that it would be nice if support for fonts could just be 
compiled in if found and not otherwise.

So what if there were something like try/catch for imports?

This works in Python, of course it's no problem there because imports 
are done at run time.  But it is a fairly commonly used idiom there, 
which says to me that if it exists it will get used.

Anyway, I seek some better way to control various optional dependencies 
than lots of --version flags.

--bb