Version support for IPC protocol.

[cheatfate]

We talked about this in Devcon4 workshops to add version support to IPC protocol.

[raulk]

Context: binding implementors are missing a version number in the protobufs. Could be added only in IDENTIFY? Should be an easy add.

[vyzo]

Sure, we can add it to IDENTIFY.

[autonome]

@vyzo @raulk Still valid request? Do we have unix socket based ipc or is this for something else?

[vyzo]

we do have unix socket based ips, that's for identifying the actual ipc protocol version.