Adapted startFromInputFile to new fabulous ParameterTree property.

Shows how the tree can be easily accessed from any- and everywhere by something
like 
typedef typename GET_PROP(TypeTag, PTAG(ParameterTree)) Params;
...
double tEnd = Params::tree().template get... 

If startFromInputFile is used, at least three parameters have to be
given in the input file: SimulationControl.tIni, SimulationControl.tEnd,
SimulationControl.gridName
These names should be discussed as soon as their creator Philipp is back. 



git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@6394 2fb0f335-1f38-0410-981e-8018bf24f1b0