Cleaned up some minor issues.

Fixed MUST for ORO to include SOL_MAX_RT/INF_MAX_RT (RFC 7083, Ticket #51).
Fixed some missing periods in options sections (option field descriptions).
Fixed section 5 to change DHCPv6 to DHCP in keeping with rest of document, missing section references, and removed paragraph in 5.5 as to whether IA_TA has value.
Fixed issues in Appendix D (heading, IAADDR should not allow Status Code?, Relay-Forw/Reply should allow Vendor Info - DOCSIS uses it).
And, a few other minor nits.