Tensor analysis package.

This is a separate version of what_we_commited_to_sympy.


Consists of:

Arraypy class - N-dimentional arrays

TensorArray class - N-dimentional array with contravariant and covariant indicies.

Classes declared in arraypy.py file.



There is also modules:

1) tensor_methods.py       - Tensor algebra.

2) tensor_fields.py        - operation in tensor fields like diff, rot, lie, etc...

3) riemannian_geometry.py  - tensor operations about some riemannian geometry

4) helper_functions.py     - some help functions.


Additional info will be later.
