Remove duplicate doubles sorted views

[leerho]

This had a rippling effect across a number of files. This also includes some trivial fixes for spelling errors and other minor issues.

[leerho]

Summary of changes by file:

hllmap/

• UniqueCountMap - added one line comment

kll/

• KllDoublesSketch

  • changed variable kllDoublesSV to doublesSV
  • Moved create from sketch code from SV to here

• KllDoublesSketchSortedView - removed

• KllItemsSketch - minor comment changes

quantiles/

• CompactDoublesSketch - fix spelling

• DirectDoublesSketchAccessor - added blank line

• DirectUpdateDoublesSketch - propagated variable name change

• DoublesArrayAccessor - line reformat

• DoublesBufferAccessor - line reformats

• DoublesSketch

  • changed variable classicQdsSV to doublesSV
  • grouped the "SortedView" methods together at the bottom

• DoublesSketchSortedView moved from /quantiles/ to /quantilescommon/

• DoublesUnionImpl - propagated variable name change

• HeapUpdateDoublesSketch - propagated variable name change

• ItemsSketch

  • Moved create from sketch code from SV to here (this had two revisions, which makes it more complex to view the diff)

• KolomogorovSmirnov

  • This needs more work to remove the dependence on the specific classic DoublesSketch and use the SV directly. This will enable its use with KllDoublesSketch as well. This will have to be a separate PR.

• DoublesSketchSortedView - moved from quantiles to quantilescommon

tdigest/

• TdigestDouble - This was to fix a conflict caused by interleaved pushes to master from Alex and me.

/test/...

quantiles/

• CustomQuantilesTest - gets the SV directly from the sketch
• UtilTest - corrected the access point

quantilescommon/

• CrossCheckQuantilesTest - corrected the access points.
• ReflectUtilityTest - corrected the access points.