unnamed register pasting

Originally reported by: **Anonymous**

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GNU Emacs 24.5.1 (x86_64-apple-darwin15.0.0, NS apple-appkit-1404.11) (in terminal.app)
Latest melpa version of evil
OSX 10.11.1

this is a very similar issue to #566 though that issues solution doesn't seem to work in this instance.What I have done to allow for access to the system clipboard in the terminal is install the simple clip package,and to use these settings for the "inter program paste function":

```
#!

(setq interprogram-cut-function 'simpleclip-set-contents)
(setq interprogram-paste-function 'simpleclip-get-contents)
```
this appears to be a way to have the clipboard=unnamed behavior that vim has but reliably in the terminal. the only problem is that even with

```
#!

(fset 'evil-visual-update-x-selection 'ignore)
```
the unnamed register is still overwritten before the paste action. i know almost nothing about elisp so I haven't been able to fix this myself or find the explanation for this. thanks for any help!

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- Bitbucket: https://bitbucket.org/lyro/evil/issue/596

Reproduce the issue in terminal Emacs with simpleclip and the shown interprogram-cut-function, interprogram-paste-function, and evil-visual-update-x-selection settings. Start by tracing Evil's unnamed-register and paste behavior; done when pasting no longer overwrites the unnamed register before the paste action.

Written by the indexing model from the issue text.