IPv6 ND RA improvements

Table of Contents round 1 (in RE-0.99.17.7) round 2 (in RE-0.99.17.9) round 3 (in RE-0.99.17.11) round 4

round 1 (in RE-0.99.17.7)

master-PJ RE-stable-0.99 RE-testing-0.99 bug ID summary
********* ************** *************** ****** *******
fb5174a   2894cdc        b4405a1         480    zebra: fix IPv6 RA wrt interface removal
6ae93c0   349772a        0620363         665    zebra: include MTU option in RA on request
6134b87   209530f        04bedb0                zebra: fix output of IPv6 ND RA options
d660f69   c92f29e        4749015                zebra: justify some IPv6 ND RA timers wrt RFC
6bb1273   5a7ce88        88ee987                zebra: clear host bits of ND RA prefix option
aca43b6   e93a0f6        3ac05c5                zebra: use prefix_ipv6 in rtadv_prefix
6eb0c5a   286e180        479288c                zebra: freshen RFC references in rtadv
4afa50b   c316fcd        a5ead89                zebra: justify rtadv VTY commands with arguments

round 2 (in RE-0.99.17.9)

RE-stable-0.99 RE-testing-0.99 summary
************** *************** *******
c17793c        52556c1         zebra: immediately send a router advertisement if RA config changed.

round 3 (in RE-0.99.17.11)

RE-stable-0.99 RE-testing-0.99 summary
************** *************** *******
ec6a959        82b5913         zebra: use IF_IPV6_STR and ND_STR for help strings
6960598        29c84df         zebra: move more ND RA code to rtadv.c
39145ee        78893ad         zebra: move some rtadv code to helper functions
c4d10f4        0215f9a         zebra: rename variable in rtadv_send_packet()
5b751c4        0345e9c         zebra: add "ipv6 nd" configuration node
b700fd0        18b7140         zebra: remove unused zebra_if.rtadv_enable
e313fba        28317a9         zebra: use more help string macros
145bf54        afd61b2         zebra: refine suppress-ra management 
31290e4        8a613fb         zebra: implement connected prefixes for ND RA

round 4

RE-stable-0.99 RE-testing-0.99 summary
************** *************** *******
               8a83593         zebra: fix struct rtadv memory type
               78bcd77         zebra: make come rtadv function arguments const