fixed bug in absorption plot routine (calculation of equivalent absorption area always used absorption of first material)

otherwise it will block all execution on daimler pc. maybe make this a
switch in the class?

Fixing playback/pause bug in itaVA experimental GUI and also checking channel number of workspace vars to match prototype rendering instance

coordinates are given as elevation angle and not as theta angle

Adding feature for itaVA experimental GUI: volume control and signal source play-state control. Also fixing some bugs with internal variable storage.

Improving setup procedure, now catching failed call to VAMatlab due to missing DLLs and notifying user in version line edit of GUI

 please verify if .pfp fix is supported on older Matlab versions

Sorry, but that did actually bug me for the longest time....

Little typo fixes. Also adding itaVA_experimental_gui, a GUI to quickly test filters using the experimental VA configuration.

Updated itaHRTF tutorial