Allow other plugins which hook into WPSEO to use the admin_footer method without the banners (premium plugins).

Also:
* fix html validation issue with xdebug
Indentation fix
Make Text statistics class instance available to other plugins/classes
Strip shortcodes from ogdesc if any

Related to: https://github.com/Yoast/wpseo-woocommerce/issues/19
Fixed potential bug -removed switch-default where this could cause issues

Other:
* Code layout fix - reverted all the strange else { if() } changes back to proper else if{}'s
Efficiency fix
Merge branch 'release/1.5' of git://github.com/Yoast/wordpress-seo into release/1.5

Conflicts:
	inc/class-wpseo-options.php