Added NRange-based ReplaceData.
Re-order NData methods.
Added NRange::GetOffset, returns an offset within a range.
Reuse SInt32 limits for NIndex limits.
Declare kNRangeNone/kNRangeAll constants in header so usable from static constructors, formalise the "normalised range" behaviour.
Add IsFullRange/GetNormalized for container objects.
New NRange test suite.
Added NData::InsertData, allow NData objects to share subsets of data through slices.
New NData test suite.