libmlm: Fix an infinite loop, clean some of the code, and use
GLib.warning instead of stderr.printf for library.
accomodator: Set the flow of the command line program so we don't need
exit().
analyze: Use GLib.OptioContext, and set flow of the command line
program so we don't need exit(). Also, stop declaring "using" and
clean up some code.
build-sys: analyze doesn't need Gee, but it needs glib.
copy-tags: Use GLib.OptionContext.
gui: Use stderr.printf instead of GLib.warning.
tags: Switch to GLib.OptionContext. This simplifies the code a lot.
Also, move a bunch of test that we stupidly made repeatedly in
update_tags() to main().