"dissect_ip_tcp_options()" but for options that are like IPv6 options
(i.e., the length byte has a value that doesn't include the option code
or length byte).
Add an "ip_opts.h" header to declare it, and move the declaration of
stuff used by it and "dissect_ip_tcp_options()", and the declaration of
"dissect_ip_tcp_options()", to that header.
Use "dissect_ipv6_options()" for Mobile IPv6 options.
Get rid of the unused "mip6_opt_types[]" array in "packet-mip6.h".
svn path=/trunk/; revision=8015
Guy Harris