Filter parameterless PIs, and introduce sync RI
- The auto-generated GUIs currently do not support parameterless interfaces, so they must not appear in the "mini-cv.aadl" file. They can be handled directly by the gui code. - Support of Sync RIs, there are two cases (1) the calls to set/reset timers, that can be handled directly by the gui code and (2) the calls to real external code, that has to be provided by the user and linked with the shared library. An example of this second case is included in demo-simu.