CA-36092: Modifying Stunnel.connect's verify_cert argument to be tri-state.
CA-36092: Modifying Stunnel.connect's verify_cert argument to be tri-state.

The values are:
  Some true -> do verification
  Some false -> don't do verification
  None -> do verification if the file /var/xapi/verify_certificates exists

Signed-off-by: Magnus Therning <d563053cb0ea35046fc6d1a4be0e7fe773f2d276@eu.citrix.com>
Acked-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@eu.citrix.com>

djs55/forkexecd,johnelse/forkexecd,xapi-project/message-switch,xapi-project/message-switch,xapi-project/message-switch