sympy/sympy — pull request #1874 by skirpichev (2013-03-09 11:55:26+00:00)
Title: Fix return value for rsolve + misc fixes

rsolve (according to docs) should return Null, not 0, if it can't find any solution

misc: broken URL in README.rst, SymPyDeprecationWarning in test_kane2.py