Build steps:
1. aclocal
2. automake --add-missing
3. ./configure
4. make

Run:
./src/phddns -h

Advanced:
1. The key in src/phkey.h is just for test, please goto http://open.oray.com to get your own code.
2. Interactive code are in phruncall.*, this can be removed if you just want core functioning of phddns
3. You shouldn't change UDP keepalive behaviours, or you device will be rejected some day.
