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
Add branches of LambertW

fixes #7105
fixes #5215
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
Consolidate all warnings.simplefilter calls to sympy.utilities.exceptions

This is the file where SymPyDeprecationWarning is defined, so the filter will
always be set when that warning is used.

This also changes the warning to once, rather than always, which matches the
default Python warning behavior.

This does cause the SymPyDeprecationWarning to show, which by default it
wouldn't, because Python hides DeprecationWarnings by default.  This is
intentional, as we want our users to know about deprecated behavior.
Move AlgebraicNumber class to the core

fixes #8066
Add a callback function so that -k can take a variable number of
arguments.  Fixes #5228