integration of 1/(1+x**2) works but 1/(1+u**2) fails
completed by: povik
mentors: Aaron Meurer, Chris Smith
Please see http://code.google.com/p/sympy/issues/detail?id=2882 for full information on this task.
Please read https://github.com/sympy/sympy/wiki/gci-2011-landing before completing any tasks for SymPy.
Please read https://github.com/sympy/sympy/wiki/gci-2011-landing before completing any tasks for SymPy.