Site updates (0.25)

Just deployed some updates to the site (full change list here). Most of these changes are part of the integrated Git repo browsing functionality (nothing to see there yet as I haven't yet configured any repos, but most of the groundwork is now laid) but there are a couple of user-visible fixes and enhancements:

• [Fix]: Restore missing submit button in new topic form
• [Enhancement]: Use CSS to highlight "active fragment" if URL includes a fragment (for example, when linking to a comment, the comment gets highlighted)