Holiday Bugfixes (#1762)

* Don't show "not much going on" when we are actively downloading

* Swipe to paginate is now behind a flag in the user preferences.

* Added a new server setting for host name, if the server sits behind a reverse proxy. If this is set, email link generation will use it and will not perform any checks on accessibility (thus email will always send)

* Refactored the code that checks if the server is accessible to check if host name is set, and thus return rue if so.

* Added back the system drawing library for markdown parsing.

* Fixed a validation error

* Fixed a bug where folder watching could get re-triggered when it was disabled at a server level.

* Made the manga reader loader absolute positioned for better visibility

* Indentation

UI/Web/src/app/admin/_models/server-settings.ts

@@ -14,4 +14,5 @@ export interface ServerSettings {
     totalBackups: number;
     totalLogs: number;
     enableFolderWatching: boolean;
+    hostName: string;
 }