snapdiff: Drop the --version option
snapdiff: Drop the --version option

This isn't currently giving any actual information, and it doesn't fit
well with the new top-level apitrace command, (which should presumably
take care of any --version option itself).

joshua5201/apitrace,schulmar/apitrace,apitrace/apitrace,surround-io/apitrace,PeterLValve/apitrace,swq0553/apitrace,tuanthng/apitrace,surround-io/apitrace,schulmar/apitrace,PeterLValve/apitrace,tuanthng/apitrace,surround-io/apitrace,EoD/apitrace,PeterLValve/apitrace,trtt/apitrace,schulmar/apitrace,joshua5201/apitrace,tuanthng/apitrace,tuanthng/apitrace,tuanthng/apitrace,joshua5201/apitrace,swq0553/apitrace,EoD/apitrace,swq0553/apitrace,PeterLValve/apitrace,surround-io/apitrace,EoD/apitrace,joshua5201/apitrace,trtt/apitrace,EoD/apitrace,trtt/apitrace,swq0553/apitrace,schulmar/apitrace,schulmar/apitrace,swq0553/apitrace,trtt/apitrace,apitrace/apitrace,surround-io/apitrace,apitrace/apitrace,joshua5201/apitrace,trtt/apitrace,apitrace/apitrace,EoD/apitrace