wireproto: nominally don't expose "batch" to version 2 wire transports The unified frame-based protocol will (eventually) support multiple requests per client transmission. This means that the [very hacky] "batch" command has no purpose existing in this protocol. This commit marks the command as applying to v1 transports only. But because SSHv2 == SSHv1 currently, we had to hack it back in for the SSHv2 transport. Bleh. Tests changed because the capabilities string changed. The order of tokens in the string is not important. Differential Revision: https://phab.mercurial-scm.org/D2856