* issue 381.4.1: create a separate IResearchLink implementation for use with ClusterEngine
* backport: ensure StorageEngineMock assigns unique transaction ids
* delegate index normalization on the ClusterEngine to the 'actualEngine'
* remove some non-unused V8 persistents
* do not throw that many bogus assertions
* do not rely on server role being defined
* slightly better debug output for V8 context debugging
* fix collection ids in inventory response
* simplify bootstrap a bit
* slightly better error handling
* make elapsed time a queryable value
* use less memory for stub collections
* added assertions that will always make sense
* added assertions
* do not garbage-collect while waiting
* less copying of parameters
* do not show "load indexes into memory" buttons for mmfiles engine
as all indexes are in memory anyway
* when a collection is truncated via the web interface, flush the WAL and rotate all active journals
this will make close all open journals on leader and followers and make them subject to compaction opportunities
* fix invalid server id values being passed from web interface to backend
* introduce afterTruncate method for indexes
* added test case for issue #3447
* updated CHANGELOG
* don't warn about replicationFactor for system collections
* check that the queries actually use the geo index and not some other index
* properly report error in web interface
* fix some internals checks that made truncate fail for bigger collections in maintainer mode
* also run a compact() operation after a serious truncate
in order to make iteration over the truncated range much faster
when the collection is next accessed
* increase default maximum number of V8 contexts to at least 16
Frank Celler
Jan
Vasiliy
Simon