- There is no client caching of the changelog/version anymore. Instead, server returns the expiration date of its cache, and that is used by the client as well.
- There is now a "Check now" button on the client that appears when data is stale. This means that info is fetched only once and never refreshed (it was refreshed every hour before) unless the user explicitly wants to check latest version, which in turn is as stale as server info is, i.e. 15 minutes max.
- Button style is shared with the "Join a channel" feature, `.btn-small` (not `.btn-sm` to be explicit that this is not a Bootstrap thing).
- Version checker content is now centralized in the `version_checker` template, instead of being partially in the checker template, partially in the Help template, and partially in the code.
- A "Try again" button lets user attempt to fetch info instead of forcing them to reload the page.
- Use Flexbox to display a nicer version checker: icon is slightly bigger, and button is always aligned on the right.
- Changelog logic has been removed from `lounge.js` and moved into the component file.
- Changelog template is only passed what it needs instead of everything the server gives us.
- Public version now displays version checker, since server is caching things.
- Cleaner code overall.
