Initial commit of an NTP fuzzer
Fuzz NTP private messages too
Mixin Msf::Auxiliary::Scanner, switch to run_host to fix DNS lookup issues
Correct order of mixins so RHOSTS works properly
When fuzzing mode 6 (control) and 7 (private) messages, print out each version tested since these tend to take a long time
Fuzz mode 7 more correctly.  Cleanup.

Provide empty 188-byte payload for mode 7 messages, otherwise nothing
seems to response.  Provide more useful defaults for versions/modes.
Allow control over what mode 7 stuff is fuzzed.
Support only fuzzing specific mode 6 operations
Fuzz all 255 possible mode 7 request codes
Minor option cleanup
Move NTP message code to Rex::Proto::NTP, simplify option handling
Add rspec coverage for Rex::Proto::NTP
Default to only fuzzing versions 2-4
Correct private message format, update tests
Address some Ruby style issues
Add rubygems check to msftidy.  remove rubygems.
Address more style issues
Add NTP fuzzer from @jhart-r7

Looks good to me!