Misc. fixes

- No need to loadLanguage('Settings') when this language file no longer exists, uh? (Themes.php)

! Pete bug: fix_accents was called through preg_replace, rather than preg_replace_callback. (Subs-PrettyUrls.php)

! The install file probably needs to make gz/app writable, too. (install.php)
Fixed icons not getting embedded, and thus making Wedge load less smoothly. This was due to this week's rewrite of... some stuff, the one where I wanted to save some... other things, and as such added more stuff. (Class-CSS.php)

Temporarily removing PHP minification. The time savings it brings to your server aren't exactly saving me time when it comes to providing support. (index.php)
+ Rewrote YouTube embed code to allow for a resizable, responsive iframe. I'd wanted to do that one for some time. (Aeva-Embed.php, Subs-Aeva-Sites.php, sections.css)

* Skins, not themes. If I do one at a time, I'll be done in 10 years. (Themes.english.php)

! Layout fix. (README.md)