Patch for Net::ISC::DHCP to add Class, Zone, and a couple of bug fixes

key <key> {}; now accepts newline as termination for the regex.
option space doesn't require encapsulate.
adds support for conditionals,zones and classes

See CPAN: https://rt.cpan.org/Public/Bug/Display.html?id=81269 for the patch I
submitted.  I'm rolling the 4 commits into one to make it easier.