v2.0

This is a major release of Polypheny Control, introducing the following new features and improvements:

• Authentication (thanks to @VishalDalwadi)
• Upgrades for several dependencies
• Improve PID gathering on UNIX systems
• Fix issue with jar not containing all plugins
• Ignore licensee checks on builds
• Introduce setting to purge plugins folder
• Prepare for Polyfier verifications

Migration notes:
Polypheny Control no longer stores its files in the .polypheny folder, but now has its own folder in the user's home directory. The name can be configured in the configuration file and defaults to .pcontrol. Furthermore, please note that the new authentication system is enabled on default for requests not originating from localhost. To disable it, set pcrtl.auth.enable=false in the configuration file.