Fixed behavior of GUI buttons:

1. now the qt opengl main window has a state-based logic, and exports a number of signal/slots that make it easier to manage events

2. the opengl widget is refactored accordingly

3. real-time as well as non-real time behavior are correct

TODO: interaction with lua editor to be tested!
Minor change to uninstall script
Fixed logic of call to CLoopFunctions::PostExperiment().

Now the responsibility to call it is assigned to the visualization.
Made MacOS uninstall script more portable.
Fixed interaction between lua editor and qtopengl main window.