Client: add level of detail

Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>
Client: Update the graph at each five seconds

Link: https://github.com/sebhtml/Ray-Cloud-Browser/issues/35
Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>
Server: fix if the vertex is not present, return 0 in coverage

Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>
Client: fix Double click are not all consumed

Link: https://github.com/sebhtml/Ray-Cloud-Browser/issues/34
Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>