Handle args consistently, from script or cmdline

Earlier versions presumed that all non-tty invocations should read
specially formatted arguments from a piped stream.  This meant a normal
invocation style (as one would use one the command line) could not be used
within a non-interactive script, such as a crontab entry.

These changes alter the priority of processing, to look first
for arguments, and if none found, revert to stream processing if not
in an interactive terminal.

It's therefore not longer necessary to comment out the stream processing
code as was done in other
commits ([[https://github.com/skweeker/geeknote/commit/4c4570f8c4fb948dfcd7b44b585569c41e04bffa][Forcing
command-line mode]).  Command-line and stream processing can now both
co-exist.