Support whitespace-newline face

[geraldus]

Face whitespace-newline is not defined in current version, see:

https://github.com/sellout/emacs-color-theme-solarized/blob/d7f9165adf02c01ea67a2ecc31df56c7495199e6/solarized-definitions.el#L695-L704

This gives following rendering:

To have proper colouring according to screenshots from main Solarized repository I have to customize this face to inherit properties from whitespace-space face:

(custom-set-faces
 '(whitespace-newline ((t (:inherit whitespace-space)))))

---

• M-x version RET

  GNU Emacs 24.5.1 (x86_64-apple-darwin13.4.0, NS apple-appkit-1265.21) of 2015-04-10 on builder10-9.porkrind.org

• Using Emacs 24

• M-: (display-color-cells) RET

  16777216 (#o100000000, #x1000000)

• Using GUI app

[geraldus]

Fixed by #181