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.
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....
[bugfix] Allow some potentially long-running index scans in structural index to abort immediately if requested to do so (e.g. during shutdown).
[bugfix] New range index: start parameter was ignored in implementation of range:index-keys-for-field function.
Update json.xq

Add a function for simplifying annotating existing XML with json:literal="true" before converting to JSON.
Add startup timeout for wrapper ; gives eXist-db more time to get really started
[bugfix] Check for free disk space in BrokerPool should respect configuration parameter, so one can disable it if necessary.
[bugfix] Wrong timeout check: login tokens timed out immedately. They should remain valid for a few seconds or the user gets logged out too quickly if requests come in with a delay.
Make use of git.commit (instead of svn-revision) together with project.version and use current year for copyright in InteractiveClient.
[performance] Skip unnecessary type checks: arguments to optimised functions should not be wrapped into useless, additional type checks, which cause a massive performance loss. All functions overwriting Function.setArguments handle type checks themselves.

In the concrete example which led to this change, calling ngram:contains took several seconds, which came down to a few milliseconds after the fix.
Added basic Update function to expath zip module
[performance] ngram index: method for computing string offsets by unicode code points turned out to be a major bottleneck. Replacing the code to avoid String.offsetByCodePoints improves indexing performance by at least factor 2.
Fixing URLs to configuration and documentation in conf.xml.tmpl.
Added signatures for zip:update and zip:entries