FS#481 - odhcpd: make log level a UCI file option

[openwrt-bot]

EricLuehrsen:

The only parameters that odhcpd pulls from the command line are help "-h" and log level "-l#". Everything else it pulls from UCI. It would be preferred if log level came from UCI-dhcp-odhcpd, but could be an override for one-shot testing at the command line. As it is now, if someone decides to change the default log level from WARN (4) per help, and hard code this default to INFO, then we all get chatty logs until we change /etc/init.d/odhcpd. Again, it would be nice to have UCI control this as the preferred method.