Remove usermanual when building for Android

Our usermanual is based on webkit, and thats not supported in Qt for
Android. We should probably replace it with a Android native webview
somehow.

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Remove printing when building for Android

Qt for Android doesn't support printing.

Signed-off-by: Anton Lundin <glance@acc.umu.se>