IPTVRelay

preview updates

Merge branch 'master' of https://github.com/doguitar/IPTVRelay

1. In `GuidesPage.razor`, a new line of code was added to assign a new ID to `args.Model.Id` if `guide` is null. The new ID is one more than the maximum ID in the `DB.XMLTV` database. `args.Model` is then added to the database and the changes are saved. Finally, `guide` is assigned the value of `args.Model`.

Merge pull request #5 from doguitar/ffmpeg-preview

1. The `FilteredItem` class has been changed from `protected` to `public`, allowing it to be accessed from outside its own assembly.