Updating classes to use __new__ instead of init
Enable if x.is_positive is branch in series()
Workaround in Function._eval_nseries to prevent some substitutions in the Derivative

    For example: Subs(Derivative(f(x), x), x, 0).subs(x, y) ->
                 Subs(Derivative(f(x), x), (x,), (y,))

    This is a fix for failed test:
    File "/home/sk/src/sympy/sympy/series/tests/test_series.py", line 86, in test_879
      assert f(x).series(x, 0, 3) == \
Less naive lseries/nseries methods for Integral

    Detect cases, when we should expand on the integration
    variable (dummy symbol).
Correct assumptions for auxilary symbol xpos: it should be is_bounded as well
Adding Weyl group functionality
Adding docstrings and doctests
Fixing an error and adding test_args
Fixed trailing whitespaces
Merging with master
Merged
Adding test_args
expand_mul in add.py
expand_mul in mul.py
Indentation Correction
trailing whitespace
Adds tests to test_complex.py
Making deep=False if any arg of self is_Add
Fixing print statement
Actually adding test_args