Fixed bug 333891: [breakpoints] Breakpoint Undo doesn't handle duplicates

Signed-off-by: Sarika Sinha <sarika.sinha@in.ibm.com>
Fixed potential NPE.
Fixed bug 439118: LaunchConfigurationTabGroupViewer marks 'revert' as disabled when canSave() is false

Signed-off-by: Sarika Sinha <sarika.sinha@in.ibm.com>
Bug 438724 - [flex] REVEAL delta does not always work reliably

Change-Id: Idf22b5a70b0194b8c91b234db3aefc5fde28d559
Signed-off-by: Anton Leherbauer <anton.leherbauer@windriver.com>