Introduce Document sources?

[roman-yagodin]

General idea:

• Documents module can render documents from one specified source
• Document sources would have different settings and limitations
• Additional sources can be added as DLLs via configuration

Sources:

• Documents table (existing)
• Files in folder (existing)
• R7.University entity documents (division documents, edu. program documents, etc.)

Problems:

• How to provide access to external source-specific settings UI?
• Where we should store source instance settings?

Alternatives:

Maybe it would be better to provide a DNN module for each "source" type which would share same view controls? This way we stay within DNN extensions model.

R7.Documents could ship install package with base set of modules, while other extensions (like R7.University) can add its own module definition in manifest referencing R7.Documents as dependency and providing own settings control or even edit control.