README updates

Update the README files for create_local_files/, subroutines/, and utils/.
These READMEs still have a lot of work required to make them fully useful, but
this is a start.
Clean up set_plot_range

Clean up code a little in utils/set_plot_range.pro.  The way it was started to
get to me -- too messy.
Merge branch 'master' into release

Keep RELEASE up to date.