Rename class HWLDF_WordAccumulator to HWLDFWordAccumulator

Part of program to remove underscores from class names. Checked core and
600+ extensions for occurrences. All uses are in core in core are updated
in this patch.

Change-Id: Ib3094249ab192db80f1639c5e543ece84c688b9a
Merge "Rename class HWLDF_WordAccumulator to HWLDFWordAccumulator"