VP8 RTP dissector

Change-Id: Ic21d13bf8ca77ff37c2d2d229c4e8c9d8f053677
Reviewed-on: https://code.wireshark.org/review/124
Reviewed-by: Evan Huus <eapache@gmail.com>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Use IP types instead of plain strings where possible

Change-Id: Ia4a78e1ef3a7c45761cc271ecc17e7868b8456d9
Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Reviewed-on: https://code.wireshark.org/review/157
Reviewed-by: Evan Huus <eapache@gmail.com>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Alexis La Goutte <alexis.lagoutte@gmail.com>