client: Add delay option to puavo-dnssd-printer-client to ease
scripting in cases that delayed backgroup running is needed.
client: Add new call to puavo-dnssd-printer-client from NetworkManager's
dispatcher.d scripts. if-up.d seems to have a race condition with
dnsmasq dns server settings.
client: Fix makefile for NetworkManager/dispatcher.d script
client: Fix makefile for NetworkManager/dispatcher.d script better
Change printer management logic so that saved managed printer list is not
used when querying and updating printers.

Added new options:
--delete-unmanaged to delete printers that are not managed. This is used
  now for shared laptops that should not keep changes made by the user.

--no-dns-query to disable DNS queries when using --delete-unmanaged during
  boottime

--require-dns-records to instruct the script to not delete printer information
  if DNS-SD records were not found
client: Do not delete all printer information on shared laptops during boot,
        but only the unmanaged printers.
client: Remove old dnssd-printers hooks
client: CUPS always writes its configuration files as new files and then
renames the new file to the old name. This breaks the /state linking
if we just link /etc/cups/printers.conf to /state. To overcome
this we always copy cups files from the image to the /state partition
when booting. Locally configured printers should stay configured
this way and PPDs are placed under /state/etc/cups/ppd.
Clean up
Merge pull request #8 from opinsys/delayeddnssd

Delay DNS-SD queries and improve network printer management