UI cleanup, phase 4 (purely cosmetic)

UI cleanup, phase 4 (purely cosmetic)

about.asp
  - Use & instead of & in several areas
advanced-dhcpdns.asp
  - Update dnsmasq link to point to actual configuration docs
basic-static.asp
  - Clean up Notes section
  - Hostname is actually for DNS records in dnsmasq (I suppose you could
    use this as a "nickname/label" but it's really for DNS)
  - Add more precise descriptions for "Bound to" and "Ignore DHCP requests
    from unknown devices", in attempt to put an end to misconceptions and
    misinformation propagated over the years
  - "IP Traffic" not "IPTraffic"
bwlimit.asp
  - Typo (case-insensivite --> case-insensitive)
forward-basic-ipv6.asp
  - Dest --> Dst (UI consistency)
qos-ctrate.asp
  - S Port --> Src Port (UI consistency)
  - D Port --> Dst Port (UI consistency)
qos-detailed.asp
  - S Port --> Src Port (UI consistency)
  - D Port --> Dst Port (UI consistency)