Matrix.det_bareis is sensitive to ImmutableMatrix
sympify args of MatrixExpr functions

Otherwise Matrix objects can creep in
explicitly merge MatrixBases in MatAdds
matmul merge_explicit rule
matadd/matmul: fix doc and unittests

Signed-off-by: Thomas Hisch <thomas.hisch@ims.co.at>
Merge pull request #17 from thisch/mrocklin-matexpr-sympify

matadd/matmull fix unit and doctests
Added DFT matrix
MatMul merge explicit does not commut matrices
Un-XFAIL two tests.  Closes #4234; closes #4492.

Both issues have been fixed for some time, but issues have not been closed.
Both tests have been moved out of test_failing_integrals.py, since they no
longer fail.
Change the name of function
Add support for Equivalent with multiple arguments
Fixed python3 compatibility issues
Merge pull request #7277 from Tempel/cleanups

Un-XFAIL two tests.  Closes #4234; closes #4492.
Merge pull request #7250 from mrocklin/matexpr-sympify

Matexpr sympify
Minor change
PEP8 Style
import xrange from sympy core
Fix #7206: Equality with matrices.

Equality was changed to support objects with an _eval_Eq method.  This allows
objects to define alternative algorithms for determining equality.  Such a
method was implemented in ImmutableMatrix.
Merge pull request #7278 from debugger22/dft_matrix

Added DFT matrix in physics matrices
Merge pull request #7281 from Tempel/7206_matrix_eq

Fix #7206: Equality with matrices.