Update build date/ version methodology

[blthayer]

@mzy2240 - would you have time to tackle this today? I gained some information from PowerWorld this morning:

There's a way to get both the version number, and the build date in a date format: GetParametersSingleElement( "PowerWorldSession", ["Version", "ExeBuildDate"], ["", ""])

We could run this in init and simply add a version attribute to SAW. Then, we wouldn't have to mess around with any of the writing to file stuff.

[mzy2240]

Ok