update_examples and init files



While trying out update_examples to update the fft examples (which are
incorrect), I noticed that the my maxima init files are loaded.  This
causes the examples to include time information from showtime:true.

I couldn't find any way to force maxima not to load my init files.
Did I miss it?  If not, I propose we add a --no-init-files option that
tells maxima not to load any user init files.

Ray