Merged SEO Extended into WordPress SEO
When saving an empty string, the `save_postdata` function would refuse to save, this makes it properly delete the post_meta, which has the effect the user intended with the added benefit of leading to less DB load.
i18n updates

Updated cs_CZ, fa_IR, fr_FR, hu, hu_HU, pl_PL, ru_RU & zh_CN
issue 531 - clean_permalink 301 redirect issue when using https
Merge pull request #532 from pirategaspard/master

issue 531 - clean_permalink 301 redirect issue when using https
Merge git://github.com/jdevalk/wordpress-seo into Fix-settings-issues

Conflicts:
	readme.txt
Merge branch 'pr/n1_Faison' into Fix-settings-issues
Code review of WPSEO Bulk Editor code

- Added note about offering this functionality to editors/authors
- Moved script enqueueing to the  dedicated function
- Ensured main wpseo admin css file is being loaded for screen icon display
- `require_once` rather than `require`
- Various code style tweaks
- Register submenu's with their proper titles and use those
- Use `screen_icon()`
- Use of `esc_url()` & `admin_url()` for links
- Use of `esc_sql()` rather than `mysql_real_escape_string()`

@TODO: sql might be better of using prepared statements for improved security
Minor code style adjustments