Fix issue 3692 and modify tests accordingly
Tests for issue 3692
test_arit.py: tests for Mul.is_rational
Removing solve and reverting back to before
Merge branch 'master' into HEAD

Conflicts:
	sympy/solvers/solvers.py
polys: Return solutions of proper type from solve_lin_sys()
Merge pull request #1883 from Manoj-Kumar-S/substitution

ode: separable reduced equations
polys: Convert symbolic trees to PolyElement and FracElement
polys: Fixed poly/term and poly/const and added tests
Merge pull request #1889 from placasse/piecewise_fold_with_piecewise_in_cond

Piecewise fold with piecewise in cond
Fixed wrong example output in doc string of sympy.utilities.autowrap.ufuncify
Add sys.exit to coverage_doctest based on whether full coverage was achieved
Classifying order of nested functions
Merge pull request #1898 from bjodah/master

Fixed wrong example output in doc string of sympy.utilities.autowrap.ufuncify
Fix file permissions (0755 -> 0644).

modified:   sympy/core/tests/test_wester.py
modified:   sympy/stats/rv_interface.py
modified:   sympy/stats/tests/test_continuous_rv.py
modified:   sympy/stats/tests/test_finite_rv.py
Merge branch 'master' into integrals2

Conflicts:
	sympy/functions/elementary/piecewise.py
Fix assumptions on A in ode test.

The solution that is tested is only valid for A != -1.
Assume A > 0 to exclude that possibility.
Small cleanup of test_risch.py
Fix a wrong result bug in risch_integrate()

The quotient rule was mistyped in two places.
Use solve only once on the system of equations.

Use solve only once on the system of equations, instead of calling
it for each equation.