Typo in docstring
Whitespace
Add KEY_EXCHANGE flag
Add a method to check for disabled fields
Add parsing of optional fields in Type3 messages

Also adds several specs based on analysis from
http://davenport.sourceforge.net/ntlm.html
Add another type1 message to specs
Refactor individual parse methods up to Message#parse

Also replaces :padding with the more-accurate :os_version in Type1.
Add failing spec for #blank_password?
Add #blank_password? for Type3 messages
Put :unknown2 back, turns out it's necessary
No need to slice, save some allocations
Refactor version check into its own method
Clarify why we slice from index 16 to the end
Use "documentation" formatter

For rspec 3.x where "nested" no longer exists. This should fix the
travis-ci build.
Merge branch 'jlee-r7-feature/verify-password'

Conflicts:
	.rspec
	spec/lib/net/ntlm/message/type1_spec.rb
	spec/lib/net/ntlm/message/type2_spec.rb
	spec/lib/net/ntlm/message/type3_spec.rb