POM clean-up, unit test fixing, testing of new db-importer, OLS testing, version unifying and a few workarounds for now

What has been changed:

• Update to latest PSI-JAMI version 3.0.0
• Centralised intact dependency version in master pom
• Updated Spring version to make it java 8 compatible
• Updated the OLS dependencies
• Updated to latest IntAct-Bridges version
• Unified data-exchange version. This is easier to maintain
• Fixed links which pointed to GoogleCode or SourceForge: DBImporter.java, OBOUtils.java, EnricherConfig.java (We should remove the http://raw.githubusercontent.com links. Once the OLS service is working properly)
• Added new nexus repo
• Clean-up of pom-files
• Disabled the mail sending functionally int the MailNotifierStepExecutionListener, because it was not working if we only want to run the scripts. This needs some more investigation.