adds a bit complicated mechanic to visit webpage directly
fixes bug, where the refresh thread would exit, when no data was inside the datafile
changes the timing, when threads get stopped and joined, so the possible wait is taken, while other calculations / io-ops are done
updates the install.sh script
changes quit-behaviour of the app, so it closes faster now
adds app indicator
window can now be hidden and shown again and exited with the appindicator