Merge pull request #13 from ivarne/master

Error in The Quotient Rule
Add start of complex differencing; use default arguments
Merge pull request #15 from johnmyleswhite/cleanup

Change Taylor finite difference arguments
changed epsilon choice in finite difference to match literature
Merge pull request #16 from eriktaubeneck/cleanup

changed epsilon choice in finite difference to match literature
major refactor in choice of epsilon for all finite_difference methods
added special abs fuction so complex step finitie difference can work with abs
bug fix in complex_differentiable_abs fuction
Merge pull request #17 from eriktaubeneck/master

major refactor in choice of epsilon for all finite_difference methods
Remove deprecated 'contains' function
Improve 'simplify' function
Merge pull request #21 from magistere/contains

Remove deprecated 'contains' function
Merge pull request #22 from magistere/simplify

Improve 'simplify' function
Add tests for 'deparse' function
Make 'deparse' function correctly handle parentheses
Minor enhancements
Merge pull request #25 from magistere/deparse

Make 'deparse' function correctly handle parentheses
Update tests using @test macro
Complete test updating
Merge pull request #26 from magistere/tests

Update tests using @test macro