Beta release

Bugfixes:

• attempt to fix Remote Service exceptions resulting in crashes
• better error handling if establishment of the VPN fails (e.g. because of another VPN app currently running)
• fix IllegalStateException in EipFragment causing rare app crashes

maintenance:

• refactoring eip setup logic, less ping-pong between activies, broadcast receiver and services
• improve VpnNotificationManager code
• update gradle

features:

• current ipv6 support