Bugfix and improvement for autogen.sh

[Josh Heidenreich]

Hey,

>        I wonder if instead it would be better to special case '--help' in
> autogen.sh so that if it is detected we don't write it to
> autogen.lastrun.

That is what the code does if I replace
     system ("./help.sh " . $ARGV[$pos+1]);
in the above code with
     system ("configure --help");

The idea of the extra help tool was to make it easier for newbies. Did
you take a look at what I have written so far?

Cheers,
Josh