Remove commented out code

[aaronayres35]

This PR simply removes a few sections of commented out code

[rahulporuri]

LGTM. Not sure what _pickles is.

[rahulporuri]

Note that there are a couple of other instances of _pickle* that are commented which can also be removed. And if i understand correctly, we can also remove the persistence related methods - __getstate__ and __setstate__.

I tried digging and at the bottom of the search - i still find these lines commented. I don't know which PR/why these lines were commented out.

[corranwebster]

LGTM. Not sure what _pickles is.

It looks like it's used by the Serializable class: https://github.com/enthought/chaco/blob/e3423614d654a203bd82ee087c085abe13b465b1/chaco/serializable.py which even has tests https://github.com/enthought/chaco/blob/e3423614d654a203bd82ee087c085abe13b465b1/chaco/tests/serializable_base.py but isn't used anywhere in Chaco.

Modern usage would be to mark traits as transient if you don't want them serialized (which is automatic for property and delegate traits).

The whole system can probably go.

[corranwebster]

I've added #583 for dealing with __getstate__ and __setstate__.

The _post_load methods are more interesting, because they hint at things which might go into a traits_init function and allow simplification of __init__ functions, but that's a bigger and more complex job.