Fix pow simplification for positive rational powers
Add tests for negative rational exponents
Comment out some tests from `test_function.cpp`

Also removed some print statements.
Some simplifications
Merge branch 'master' of https://github.com/sympy/csympy into pow_simplification
Add new tests, uncomment some of the tests
Update `Pow::is_canonical`
Fix a bug, and add a test for Pow::is_canonical
Add the test from `test_printing` that failed before the last fix
Fix the assrtion check
Use Integer(q) instead of *integer(q) and fix a typo, explicit check for Rational
A complete restructuring of `pow`
Remove the commented out code
Merge pull request #227 from thilinarmtb/pow_simplification

Fix for #224: Fractional radical simplification