Fix the download URL for stable release jars
Add debugging information to UpgradeChecker
Woolz: make sure the service is initialized when calling openBytes

If planes are being opened after initialization from a memo file, the service may not have been
set up.  This attempts service initialization any time the service is null during an openBytes call.
Merge pull request #969 from melissalinkert/wlz-openbytes

Woolz: make sure the service is initialized when calling openBytes
Merge pull request #941 from melissalinkert/upgrade-url

Fix the download URL for stable release jars