changes:
original .bb file is based on dhcp3, whose build system differs from
dhcp 4.x, add a new dhcp4.inc and preserve dhcp3.inc for reference,
this should fix the conf file location bug of dhclient/dhcpd 4.1.0
- defining _PATH_DHC{LIENT,PD}_CONF in make parameter no longer works,
put these definition to includes/site.h
- delete upstream version of conf files, which are not used, and
with an installation path hardcoded to ${sysconfdir}
- similar thing happen for leases file, use new configure option to
specify
- RANLIB, LIBDIR, etc. as make parameter are no longer necessary
