Control external images display

[fenbox]

Is your enhancement request related to a problem? Please describe

In some cases, referencing external images may involve privacy risks.

Describe the solution you'd like

Provide an admin option for whether external images are displayed by default:

• Option 1: Always display external images
• Option 2: Ask before displaying external images

A prompt is given on the page if set to "Option 2", and the user can allows the current page image to be loaded.

Describe alternatives you've considered

Provides an option to remember in browser and show images the next time visit.