convert radius to float before using for cylinders
Merge branch 'development' into export
show lines for connections, display color for visual group elements that
have no value and unit
pings existing client connections whenever a new client is created, and
disconnects those that client don't answer the ping anymore.
adding min and max intensity values for visual groups in tree widget
Release 0.2.0
Merge branch 'development' into export

Conflicts:
	src/main/java/org/geppetto/frontend/controllers/GeppettoServletController.java