Re-organize initialization so that User-Agent CVar actually works.
Add web.headless CVar to not load CEF even on graphical client.
Clean up init logic to not rely on static IoC, and clean up loggers used too.
* Trying to get res:// and usr:// cookies to wrok
* Update CefGlue
* Bump CEF
* Seal types in WebView
Fixes warnings
* Move most of client cleanup to game thread.
This used to run in the windowing thread which broke CEF shutdown, most notably cookie saving.
* "flushcookies" command for CEF.
* Remove unecessary res:// code.
* Fix tests
* More request handler fixes.
* Good thing I don't have to care about commit quality in PRs like this.
