Add CSE for MatrixExpr adds (WIP)
Remove MatrixExpr support (WIP)
Add negative coefficient optimization (WIP)
Add negative exponent optimization (WIP)
Add new way to optimize CSE (WIP)
Do better Pow optimization (WIP)
Order Mul argumnets (WIP)
Do better Pow optimization (WIP)
Make tests to comply with new cse (WIP)
Fix for Python 3 (WIP)
Add test to CSE non-commutative replacements (WIP)
Add 'Add' CSE terms oredering (WIP)
Make optimizations substitutions use eval=False (WIP)
Fix dict comprehension for Python 2.6 (WIP)
Fix use of CSE in tests (WIP)
Put fast CSE functions inside cse_main.py (WIP)
Put fast CSE functions inside cse_main.py (WIP)
Reorganize CSE functions (WIP)
Add some comments and docstrings
Remove prev_cse() and make new cse() to deal with Matrix(s) as prev cse