Bump central version to 2.0.0-SNAPSHOT and examples to 3.0.0-SNAPSHOT

Signed-off-by: Fred Bricon <fbricon@gmail.com>
JBIDE-18819: Always show Software/Updates tab
JBIDE-18652: More elegant logging instead of NPE
JBIDE-13904 - Minor UI issues in 'Configure Repositories' wizard