Added an option to work without GUI. It should be specified in QSettings what to do with update.
Modified QSettings to point to external variable instead. The application should supply the settings (to enable more specific QSettings usages).

Signed-off-by: Alexandr Zarubkin <azarubkin@gmail.com>
Merge pull request #7 from me21/autoupdate

Added an option to work without GUI. It should be specified in QSettings what to do with update.