IXLRangeIndex defined ...

Range indexing using QuadTree implemented
Replace searches of intersected ranges with the optimized version

Сonsolidation of conditional formats and data validation rules (#761) ...

* Failing test added

* Multiple ranges for conditional format

* Clearing ranges of CF fixed.

* XLConditionalFormat.Range implemented via Ranges.

* Tests for CF copying added

* XLRangeConsolidationEngine implemented

* Conditional formats consolidation re-implemented.

* Data validaton rules consolidation implemented

* Tests fixed

* CF formula adjustment implemented

* Fix clearing formats not covered by cleared range

* Reference files updated (uncertain about changes). Adjusting CF formulas fixed

* Fix multi-range conditional formats loading. Fix CF consolidation to prevent reordering of rules.

* Fix formula shifting for multi-ranged conditional formats.

* Merge conflicts solved

* Range property made non-obsolete and returning First rather than Single