[TEST] use higher timeout to wait for balanced cluster

CorruptFileTest sometimes hits conditions where lots of rebalancing
happens. In such a case the default timeout is just not enough - this
timeout just makes sure that the cluster has enough time to balance
itself.
Add version check before reading script type in UpdateRequest
Indexed Scripts/Templates: cleanup

This commit cleans up some code around the indexed script/templates feature.
Remove dead code in ScriptService.
Remove setXScript methods for UpdateRequestBuilder and use setScript(script,type) instead
Added missing version based serialization
[TEST] Fix test to use keyword analyzer since it relies on exact terms without processing
[SEARCH] Wrap filter only once in ApplyAcceptedDocsFilter

We potentially wrap the given filter multiple times when iterating the
subreaders. We only need to do this once.

Closes #6873