package/netifrc: new package

package/netifrc: new package

netifrc entirely replaces openrc's basic network management. As such, it
conflicts with the network services installed by openrc, so we remove
them from openrc when netifrc is enabled.

Currently, we only catter tfor the loopback interface, but we prepare
for also handling the DHCP interface, to come in a latter patch.

Signed-off-by: Michał Łyszczek <michal.lyszczek@bofc.pl>
[yann.morin.1998@free.fr:
  - remove openrc files within the openrc package itself
  - as it's a generic-package, no need to use post-install hooks
  - use description from the homepage in the help text
  - check-package fixes
  - rename package
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
[Thomas:
 - pass UDEVDIR to install udev rules at the correct location]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>