IndexRangeBlock working for hash indexes.
Merge branch 'aql2' of ssh://github.com/triAGENS/ArangoDB into aql2
making useIndexRange abort if it encounters a limit node.
Merge branch 'aql2' of ssh://github.com/triAGENS/ArangoDB into aql2
IndexRangeNode now working with skiplists.
Merge branch 'aql2' of ssh://github.com/triAGENS/ArangoDB into aql2