ADT: Suggest solution to ADT version check error.

This amends the ADT version check to help the user either:
- open the SDK Manager
- open the P2 Updater
- open the Android Preference

On Windows the launch the *external* SDK Manager since
eventually we know that ADT will lock something that would
prevent the update from working in the first place.

Change-Id: Ib20e4e1411b36e3cd794cccbc02518db0a40ced9
14 files changed