A1 overrides: add missing PureVPN networks and clean up

A1 overrides: add missing PureVPN networks and clean up

GZ Systems Ltd. has some other networks which were not added to A1 overrides
by mistake. To clean up the list a little bit and make file processing faster,
some of the networks were allocated in bigger ones (>= /23).

Sorry for this large patch, but I guess it does not make much sense to add
a bunch of networks fist and then split them apart afterwards. :-|

Signed-off-by: Peter Müller
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>