Fix calculation sign() of Mul, see #3677
Add missing tests for issues #3677 and #847
delay im(a) calculation
Merge pull request #1 from smichr/sign

delay im(a) calculation
Added support for rational inequalities (#3528, #3448)

In [1]: from sympy.solvers.inequalities import *

In [2]: reduce_rational_inequalities([[(x**2 + 3*x + 2)/(x**2 - 16) >= 0]], x, assume=Q.real(x), relational=False)
Out[2]: (-∞, -4) ∪ [-2, -1] ∪ (4, ∞)

In [3]: solve((3*x + 1)/(x + 4) >= 1, x, assume=Q.real(x))
Out[3]: 3/2 ≤ x ∨ x < -4
Merge pull request #1852 from skirpichev/3677-fix-sign

Fix calculation sign() of Mul, see issue 3677
Merge pull request #1856 from smichr/ratineq

Added support for rational inequalities (#3528, #3448)
Rewrite of harmonic numbers into summation
Test rewrite of harmonic numbers into sums
XFAIL the test case for this code

The code is correct but due to issues with dummies we can not test that.
Merge branch 'harmonic_number' of github.com:raoulb/sympy into harmonic_number