The connection to the database now works in a more robust way.
Started the development of the new metric for the workload percentage.
Merge branch 'master' of https://github.com/deib-polimi/modaclouds-space4cloud

Conflicts:
	src/it/polimi/modaclouds/space4cloud/gui/RobustnessProgressWindow.java
	src/it/polimi/modaclouds/space4cloud/gui/SolutionWindow.java
	src/it/polimi/modaclouds/space4cloud/mainProgram/Main.java
	src/it/polimi/modaclouds/space4cloud/mainProgram/Space4Cloud.java
	src/it/polimi/modaclouds/space4cloud/optimization/OptEngine.java
	src/it/polimi/modaclouds/space4cloud/optimization/solution/impl/SolutionMulti.java