FractionalArithmetic

FractionalArithmetic was written to support woodworking when using fractional inches and not millimeters.
There is a smallest unit of fractional arithmetic that woodworkers are used to working with, in my case
it is 1/32".  If I make my default base 32, then all computations requiring a final result to be reported
as a nearest fraction will result in a dimension of 1/32" or greater.  So when I set up a machine to conduct
an operation I know the accuracy I should be dialing in.

The FractionalArithmetic module uses the "rational" implementation in Ruby core.  However, the FractionalArithmetic
extends the numeric value by taking in  a string and converting it to a MixedFraction (MF) value.
MF can be added, subtracted, multiplied and divided by another MF value or a numeric value.
Additionally, the base can be exchanged to a new base for an MF value.  An MF value
can be printed out or converted to a string where the fractional display is available to the user.

Lastly a decimal value can be converted to an MF value or an MF value convert to a float with to_f.

LWD is a class provided for Length, Width and Depth joining of rectangular shapes.  This class provides
the basis for solid modeling.  A class instance is able to form the union or intersection of two rectangular
solids based on the common dimensions.  So a rectangular solid with LWD and a second solid the length, width
and depth dimensions are taken as common to both.  Lastly, a tally method provides a summary of all dimensions
and finds commonality in face views to report the total having the same dimensions.

fractionalArithmetic_spec demonstrates the use of the module methods and expected results.