Added functionality to recognize 2D named objects
Fixed failing specs, split new functionality between With2DNames (applied to Array and Matrix) and With2DSizes (only applied to Array)
Fixed named_2d? not returning booleans
Make row_by_name and column_by_name return named arrays
Added support for cases when only one dimension of names is specified
Merge pull request #11 from nessche/2d_names

2D Names functionality for Arrays and Matrices