Ignore errors on pdf generation

Signed-off-by: Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn@axis.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Generalize ignores of generated documentation

Signed-off-by: Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn@axis.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Printing: only give up if no size is available

Checking for available printers appears to sometimes fail, even if there
is a valid PDF or PS printer.

Instead we bail if we can't get a valid size for the printer.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>