Make model and datacenter objects serializeable

We need that to be able to support repeatable runs
Store datacenter list into mongodb and load it again based on config

This allows repatable runs with different algorithms.
Cache loads in DB as well
Switch to generated data by default and enable logging
Add repo interface

Forgot to git add it ...
Merge remote-tracking branch 'origin/repeatableRuns'

Conflicts:
	cloudSimulator/src/main/java/cloudSimulator/algorihms/DataCenterMigrationBestFit.java