* allow to access last operation tick of the transaction
* modify IResearchLink to rely on last commtted tick
* get rid of writing arangosearch markers to WAL
* further implementation
* local changes in iresearch
* add recovery states
* properly handle link creation during recovery
* adjust test cases
* properly handle nested transactions
* ungreylist recovery tests
* add more recovery tests
* do not use transaction to pass recovery tick
* do not store recoveryTick in MMFilesRecoveryState
* adjust tests
* fix mmfiles
* cleanup
* add context validity check
* fix tests
* fix more tests
* ensure subscription is not being released during commit
* address review comment
* final cleanup
* fix crash
* fix tests
* address test failures
* address review comments
* address review comments
* properly set recovery tick even if no recovery happened
* move IResearchViewSort into separate unit
* ensure sort is propagated to IResearchLink
* update iresearch and extend some tests
* implement insertion of sorted values, store value comparator in link
* add tests for VPackComparer
* minor cleanup
* fix issue with sort definiton propagation
* propagate error message from index factory
* add integration tests for sorted indexes, single server
* initial implementation of IResearchViewMergeExecutor
* move iresearch::VPackComparer to separate translation unit
* store collection in IndexReadBuffer for IResearchViewMergeExecutor
* set primary sort from optimizer rule
* add some tests for sorted view case
* extend IResearchViewNode tests
* simplify primary sort definition
* pretty print order condition covered by arangosearch in query explanation
* fix compilation with g++-8
* address catch test failures
* fix tests
* adjust arangosearch optimizer rule to optimize sort in case of cluster
* make tests for sorted indexes work in cluster too
* fix tests
* extend js tests for sorted indices
* fix keyword in query explainer
* ensure sort-limit rule works with views
* backport ngram analyzer fix from upstream
* address jslint errors
* modify IResearchViewSort to support boolean direction specification format
* add some tests
* add tests
* add skip functionality
* extend tests
* add more catch tests
* inline some methods
* address jslint errors
* extend catch tests to reproduce the failure
* add some tests for check fullcount
* add more tests
* extend tests
* temporarily comment out broken tests
* extend js tests
* address review comments
* address jslint errors
* update iresearch
Andrey Abramov
Dan Larkin-York
Jan
Jan Christoph Uhde
Simon