jsPlumb 1.3.15 -> 1.5.3 RC
Improve Statemachine viewer

* some improvements.
* adapt to jsPlumb 1.5.3
Merge branch 'master' of github.com:Heigvd/Wegas

# By Benjamin Gerber
# Via Benjamin Gerber
* 'master' of github.com:Heigvd/Wegas:
  Resolve #295