Summary:
Draft-22 onwards uses two one byte length fields to encode connection ID length instead of one one byte length field.
To support this without disrupting existing clients we need to make our parsing version dependent. This diff accomplishes it by special casing the existing Facebook client QUIC version (0xfaceb000), and changing the default Facebook client version going forward to 0xfaceb001.
Note that this diff also changes the behavior of the ticket transport parameters. When we changed from draft-18 to draft-19 transport parameters I apparently forgot to update the ticket transport parameters to the new format.
Reviewed By: yangchi
Differential Revision: D16205090
fbshipit-source-id: e74a92fa959d308f4bb43bad76e58d4b58d07322
