WIP: histogram explorations
Further work towards generic histogram code
More progress on generic histogram implementations
Work in terms of frequency distributions
Minimize memory use
Substatntial redesign of histogram classes
Eliminate bin center testing with truncating types
Add more test code
Add true multidim capabilities

An n-dim histogram classifies n-dim input values into bins. We still provide
a 1-dim histogram for ease of use.
Document classes
Enhance histogram api

Now histograms can report info about their boundaries
Define getBinCount() for histograms
Change how extreme values are counted

Now when no tail bins are specified values outside the data range are not
counted in any bin of the histogram. As part of this change the bin position
calculations were somewhat changed.
Rename bounds checking methods
Add more input value error checking
Remove obsolete code
Change how bin positions are mapped

At the same time make test code better
Tighten up input error checking
Implement Dimensions interface
Make getBinPosition() similar to other code

The Real1dBinMapper code was refacotred previously. Make sure those changes
are pulled into this class.