Add to the define-javascript-library/with-js-libraries scheme a way
to avoid reloading libraries we have already go.  This involves defining
a predicate for each library that detects if it is present.

Put log4cl::memory-accumulator into it's own file.

Change the default window so it's only got a bit-o-text in it,
move the plot/flot example into examples.

Add an optional bollean arg to the demo function that makes
it run faster, to fast for viewers but better for testing.