genericInitGui is introduced

1. runGui is modified to return the variable name for the started program
2. In MyInstrument, the class input parser is renamed from Parser to ConstructionParser and createConstructionParser is also returning the value together with assigning it to the MyInstrument property (the latter is for notational brevity).
3. In Gui's added functionality to clean the global variable on exit. For this an input parser was introduced.
4. genericInitGui is introduced to handle the window auto naming and instrument connection with a given class