* 'engine-api' of https://github.com/arangodb/arangodb: (46 commits)
Merged RocksDBPathBasedIndex into RocksDBVPackIndex.
fix handling of externals
fix toArray()
fix returning documents
Added hash-, skip list, persistent indexes
harmonize filtering - filter on full filename.
mini modifications
standardize starting of servers for replication tests
Edge index compliant with design doc
another fix for #2404
Moved „removeLargeRange“ method to commons
Added length byte to IndexValue keys.
fixed issue #2404
Added drop to primary index
Added drop() to indexes
Fixes a coordinator crash in Clustered Traversal. In case of failover during query planning.
Fixed edge index
Expand on CORS documentation
Let ArangoDB handle the allow-credentials header
make the authentication tests run on directories
...
* 'engine-api' of https://github.com/arangodb/arangodb:
fixed serialization bug
warn before we run out of file descriptors
updated CHANGELOG
slightly simplify logging