initial implementation of sympy.physics.quantum.pauli, containing the pauli sigma operators and states that they act on
made pauli operators commute with boson operators
fix bug in use of warnings module. improved support for normal ordering expression of products of mix of differetnt types of operators
improved support for simplification of products that includes an identity operator
Fixed bug in handling of non-operator base Pow instances in sympy.physics.quantum.operatorordering
support for indices for Pauli operators the in quantum.pauli module
Added docstring to lambdified functions

If arguments have names, that is used. Otherwise the stack is inspected
to determine if the name can be inferred *with certainty*. If there is
more than one variable pointing to the object, then the name cannot be
determined with certainty, and 'arg_#', where '#' is the number of the
arg is used.
Added args test. Fixed code style error. Fixed missing import bug in unit test.
added a few more tests for pauli module. fixed bug in unit test.
fix white spaces
added newline at end of file
removed trailing white space
added docstrings and docstring tests/examples
Merge branch 'physics.quantum.pauli' of github.com:jrjohansson/sympy into physics.quantum.pauli
added more unit tests for pauli sigma operators
added more unit tests for quantum pauli operators
integrals: An amendment to spde()

The iterative version of spde() currently assumes that the
coefficient  a  of  Dp  were invariant in the loop, in which
case the values of the multiplier  alpha  are powers of  a.
Otherwise the offset  beta  of the solution will be incorrect.

I have added two test cases where  a  is not invariant.
In the general case,  alpha  can be used instead of a power of  a
to construct the correct value of  beta.
Vector pretty print test fix. Fixes issue #7679.
Codegen: Use the first function name as a default for prefix

Allow an abbreviated call to codegen:
codegen(("foo", 2*x*y), "F95")
rather than specifying "foo" twice:
codegen(("foo", 2*x*y), "F95", "foo")

This is particularly nice for languages such as Octave where the
filename (prefix) should match the function name.
pretty_symbology: Don't assume the output of U() is not None

U() returns None when unicodedata can't be imported. I'm not sure how to test
this because it's only reproducible if unicodedata from the standard library
can't be imported.  I suppose we could add a hook to test it. It won't be
straight-forward though because the key thing is to make sure it works
correctly at import time.

Fixes #8163.