The new option command allows stap to change the behaviour of stapsh
depending on the scheme used. For now, only "verbose" is a valid option.
This is especially useful for the unix scheme, where we connect to an
already running instance of stapsh. Options are sent to stapsh right
after a successful handshake.
- remote.cxx: send options after successful handshake
- staprun/stapsh.c: add option command and verbose option