GUI update, create out_dir, drop rusages on Win

1) If output folder doesn't exist, code now creates it.
2) Rusages disabled for Windows because functionality resource is not
available on Windows.
3) Some changes to GUI, including addition of option to set focal node
currents to zero (this was only accessible via .ini file before).
Changed to always write log file to output dir

Changed logging due to incompatibility of resource library with Windows.
Now saving log file to output directory to avoid problem with re-use of
.ini files leading to writing of log files to
unintended locations (ie when user loads settings from a different run
and changes output location, they wouldn't expect log file to be written
to old output dir).