[!] significant optimization of chat window (both themes), reduced number of images and their sizes
- tabs in settings: Optional Services, Themes preview
- better French and Spanish translations, additional languages are stored separately
- detect Chrome browser, show its version
[!] reverted order in title, removed available_locales variable from config.php (detect automatically)
[!] return English message by default (when translation for other language is absent)
[!] problems with styles, fixed error messages in avatar uploading
- nice confirmation when form is saved