radvd: add from OE-Classic, update and tidy up

* Update to 1.9.1
* Add libdaemon to DEPENDS as needed by 1.9+
* Remove empty config file (not really of much use and there's an
  example config in the -doc package anyway)
* Use useradd.bbclass to create user
* Handle hardcoded paths in initscript
* Add LSB headers to initscript (borrowed from openSUSE)
* Set custom LICENSE as it's BSD-Style but not actually one of the
  standard BSD variants
* Add LIC_FILES_CHKSUM
* Set SUMMARY (which sets DESCRIPTION)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>