Trait failes are merged in three files:
* operations.rs - for low-level matrix/vector operations
* geometry.rs - for operations with a clear, broadly known geometric meaning.
* structure.rs - for operations to access/alter the object inner structures.
Specialisations are moved to the `spec` folder.
Traits like `AbsoluteRotate` and `RotationWithTranslation` have been moved to a `comp` folder
containing any trait providing operations which are combination of several traits.
Now, access to vector components are x, y, z, w, a, b, ... instead of at[i].
The method at(i) has the same (read only) effect as the old at[i].
Now, access to matrix components are m11, m12, ... instead of mij[offset(i, j)]...
The method at((i, j)) has the same effect as the old mij[offset(i, j)].
Automatic implementation of all traits the compiler supports has been added on the #[deriving]
clause for both matrices and vectors.
