Improved design

Deleted templates/404.html, templates/500.html, templates/_formhelpers.html, templates/account.html, templates/change_password.html, templates/dashboard.html, templates/dashboard_header.html, templates/embed_conf.html, templates/gallery.html, templates/header.html, templates/image.html, templates/index.html, templates/login.html, templates/register.html, templates/url_conf.html, main.py files