give the user some feedback

Signed-off-by: Lehner Florian <dev@der-flo.net>
remove message from statusbar if syncing fails

Signed-off-by: Lehner Florian <dev@der-flo.net>
validate the url from user input

Signed-off-by: Lehner Florian <dev@der-flo.net>
update address book list after checking for new one

Signed-off-by: Lehner Florian <dev@der-flo.net>
add serverConnectionTest() and upgrade getSingleInt()

Signed-off-by: Lehner Florian <dev@der-flo.net>
force the user to input a valid url

Signed-off-by: Lehner Florian <dev@der-flo.net>