knxd: add one uci option for one cmdline arg. add a lot comments in the config file (closes #2233)
Signed-off-by: Patrick Grimm <patrick@lunatiki.de>
Acked-by: Othmar Truniger <github@truniger.ch>
[Squashed patches from PR into single one, bump PKG_RELEASE]
Signed-off-by: Michael Heimpold <mhei@heimpold.de>