Prevent NPE as reported in https://github.com/eXist-db/exist/issues/254
Smaller code improvements
Avoid NPE for corrupted resources on backup, open query dialog, listing and intentional removal of them in java admin client.
Merge pull request #261 from dizzzz/community_support

Improve SQL extension
Bugfix: BCC list was not iterated
Reviewed MAIL module code, made improvements (readability)
Continued improvement of the MAIL module: better readable null.empty string checks, probably better to use the isBlank() method.
made a manual mistake....
Merge pull request #263 from ljo/develop

Avoid NPE for corrupted resources on backup, open query dialog, listing ...
Merge pull request #265 from dizzzz/cherry-pick

MAIL module improvements
Merge branch 'develop' of github.com:eXist-db/exist into java7_changes