Update some of the setup scripts and add new rtdev-install script

I think the setup process is too complex and there are too many
scripts currently.  It is hard to keep track of what each one does and
when to use which one. This introduces a rtdev-install.sh script that
is a first attempt at being the one script needed for installing a set
of devrels for a particular release.
Add tools.mk file and update Makefile to use it
Allow distinction between console and file logging levels

Move from a single lager_level configuration option to
lager_console_level and lager_file_level in order to be able to
control these independently. The default level for the console output
is notice to minimize the output display during a run. The default
level for the file output is info in order to capture all of the
logging that previously has been output to the console.