v2.1: Updated to MIT license; Feature additions for copy/paste and streamlined default options

What's Changed

• Relicensed the project from Apache 2.0 to MIT by @fcgreg in #3
• Change default output mode to hashonly with MD5 by @fcgreg in #4
• Make GUI status and summary text selectable by @fcgreg in #5
• Enable copy from Match Preview table rows by @fcgreg in #7
• Show the release version in the GUI window title by @fcgreg in #9
• Show the release version in CLI help and add a version flag by @fcgreg in #11

Full Changelog: v2.0...v2.1