- Scriptcontext debugged to be working

- Added a drivable adapter to scriptcontext nodes
- Added subsampling to simulated histograms (and as a general option) in
  order to support Gumtree testing.

histogram.w

@@ -234,6 +234,8 @@ only these few functions operate on histogram memory drivers in general:
    void        DeleteHistDriver(pHistDriver self);
    int         HistDriverConfig(pHistDriver self, pStringDict pOpt,
                                 SConnection *pCon);
+   HistInt *DefaultSubSample(pHistDriver self, SConnection *pCon, 
+   		int bank, char *command);                              
 @}
 
 CreateHistDriver creates a new HistDriver data structure and returns it. Or