Move scrollview to initial position on reset zoom button click
Limit state drag movements in sm-zoom div
Change styles:
* Initial state -> double border
* Dialogue state -> blue border
* State -> red border
* Dialogue transition -> blue arrow
* Transition -> red arrow
Fix adding state when there's only one available state type
Show transition edit form on click event
Merge branch 'master' of https://github.com/Heigvd/Wegas