modified to exclude all files generated by Visual Studio and other programs
added calculator and calculator.test project skeleton.
implemented basic fucntionality.
Added list related functionality to calculator.
clean the code.
refactored the code.
refactored code and added tests.
added xml comments to methods and classes
Changed the spelling of subtract method.
created new class for all assertion tests.
added all assertion test class
Updated method to add exception handling for testing assertions.
Added more assertion tests.
Added exception handling for AddList method.
Added more assertion related tests.
Fixed Assert.NotInRange tests.
added test class for all attributes.
added more tests
Merge pull request #3 from dgpuranik/dev

Dev