End case: no bar candidates

Check if the various filtering steps of the algorithm eliminates all
barline candidates. In this case the algorithm can be exited earlier
than normal and the MEI file can be written with no barline candidates.
Set internal parameters

Allow the aspect ratio threshold and the vertical threshold to be set in
the barline finding algorithm. This is so we can evaluate the barfinding
algorithm with various combinations of parameters and observe the
output.
Evaluate parameter matrix

specify parameter matrix to run with experiments with.
Stifle intermediary output images

allow the option to not generate intermediary output images. Should
speed up the experiment runs