Added method to check if double is nearly zero
Added tests for nearly zero method
Changed Solver to use nearly zero when testing if a double is zero
Merge pull request #14 from rickyrombo/delta

Delta
Added Ashu model to modelGenerator
Added Ashu model to StandardModelGenerator
Added Ashu solution to SolutionGenerator
Added Ashu Model Test
Generalized double comparison methods
Changed all double comparisons to use tolerance
Changed StandardModel to track constant term
Changed StandardModel ToString method to use constant term
Changed cnPrime calculation to be clearer
Changed solver to only select artificial variables to leave in 1st phase of 2 phase
changed equality comparisons to use tolerance with doubles
Change solver tests to allow arbitrary number of qualities to check if solution matches
Updated variable name in solver
Refactored double comparison to be separate extension class
Combined steps in determining exit column
remove debugging writelines