- prune timeout handling for barrier

- handle ok/nok more automatically for every
  DTester operation method

- write more documentation parsable by epydoc

- handle X11 forwarding in order to be able to drive X11 application

- work for pexpect/paramiko integration in order to use pexpect
  both for local and ssh pty

- design and create a default and simple test files sets
  which may be handled by each DTesters

- add options for expectFromCommand to modify its semantics ( actually next steps are executed if expectFromCommand timeout or not ) 

- when a timeout is raised, put outputs in a file and invite the user to read it

- improve monitoring for expectFromCommand : the way of monitoring is too simple and probably innefficient when the session output is huge 
