Removed Bootstrap from Default Theme. Default Theme is super plain.
Made a new theme in the App instead which uses bootstrap.
Added MainModule for Application (demo) so it will scan for themes in the application as well.
Made Bootstrap the default theme for Application (demo), but without it CoreModule will set up DefaultTheme.
Cleanup of theme images and stylesheets.
Fixed a bug in CachedTheme.
Additional fixes for Bootstrap theme.