Introduced an index UUID which is added to the index's settings upon creation. Used that UUID to verify old and delayed shard started/failed events are not applied to newer indexes with the same name.

Also, exceptions while processing batched events do not stop the rest of the events from being processed.

Closes #3778
Add more debug info to SimpleDeleteMappingTests
do not silently fail on plugin install with source files
use the event cluster state to send events back to master
instead of relying on the current cluster state from the cluster service, make sure to rely on the cluster state we get from the change event, this will allow us to move processing of the cluster event around potentially to before the local cluster state has been updated
Documentation: Removed service wrapper, added rpm/deb package information
Send the update-mapping events before actually indexing into the shard, because the latter may generate exceptions (like when the shard is not yet ready to accept new docs).

Also improved the SimpleDeleteMappingTest, as it make take a while until the update-mapping event is processed.

Closes #3782
service.bat properly configures mem settings

service.bat converts X(m(s|x)|ss) to MB/KB and uses dedicated arguments to the underlying JVM DLL
empty/unset JAVA_OPTS no longer trips commons daemon
fixes #3785
remove unused setting
remove unused class
Print Java Version during Validate
Add indexUUID to mapping-updated and mapping-refresh events and make sure they are applied to an index with same UUID.

This can go wrong if indices with the same name are repeatably created and deleted.

UUIDs can not be null anymore. If UUID is not available `_na_` will be used as a value.

Also - some minor clean up in ShardStateAction where shard started events could be added twice to the to-be-applied list where the second instance will be ignored.

Closes #3783
introduced NodeSettingsSource in the test infrastructure os tests with scopes TEST & SUITE without an explicit numNodes definitions will fall back on the nodeSettings(int) callback
Returning useful exception when sorting on a completion field

Closes #3747
added a ToXContent implementation to NodeStats
Highlighting can return excerpt with no highlights

You can configure the highlighting api to return an excerpt of a field
even if there wasn't a highlight on the field.  This must be implemented
in each highlighter individually.

The FVH implementation seems to do a good job of building the excerpt.
The Plain implementation I'm less happy with.

Closes #1171
Minor parsing tweak.
Rename highlight no_results to no_matches.

Closed #1171
Documentation for highlight no_matches.

Closes #1171
Support no_matches as global highlight config.

Closes #1171
Fix typo in docs.

Closes #1171