* issue 506.3: backport 3.4: issue 506.3: use camel-case configuration parameter names consistntly, add a configuration version property to iresearch view meta
* backport: ensure meta version is supported
* backport: hide 'version' property from non-persistence json
* issue 496.3: backport 3.4: move more coordinator-related logic out of TRI_vocbase_t, rename some arangosearch view configuration parameters, remove some consolidation policies, update iresearch to revision 6fd9760d81b136f769e277ea5b8f53996ed7a1ca
* address merge issue
* backport: remove code causing nullptr access
* invalidate payload for each field in FieldIterator before setting a value
* address compilation issues
* issue 450.3: use a single configuration policy differentiated by 'type' with arbitrary number of configurable parameters
* ensure test data is persisted to the test directory
* add missed declaration
* fix typo
* add full namespace and includes
* issue 400.2.4: register IResearchView sync tasks with IResearchFeature, remove unused configuration parameter
* set flag before notify, fix failures in new tests from 'devel'
* revert set flag before notify, fix more failures in new tests from 'devel'
* fix even more failures in new tests from 'devel', backport: do not reset notification flag if pending tasks were seen
* fix still more failures in new tests from 'devel'
* try to work around buggy test failures
* issue 401.2: split IResearchViewMeta into the user configurable part and internal state
* backport: update documentation and integration tests to reflect the IResearchViewMeta changes
* backport: addresss typo
* backport: address another typo
Vasiliy
Andrey Abramov
Jan