fmdeGui: fix exception MessageBox'es

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
fmdeGui: display reference markings for axiom sets in stage 3 plots

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>
fmdeGui: display prelabeling for axiom sets

Prelabeling is the distance between reference trajectory markings and
observed trajectory marking. It is always between 0 and 1.

Labeling is constructed from prelabeling by taking
segments where the distance is less than the threshold (which is
called Precision).

Signed-off-by: Victor Shcherbinin <victorshch@gmail.com>