Need to implement a reason for proposal censorship

[sndurkin]

@davecgh mentioned this has been discussed, so I'm just creating an issue to capture it.

Currently there is no support for the admin providing a reason to the user for censoring a proposal.

[marcopeereboom]

I am ok adding this. The reason I didn't add this during development is that reasons can be misinterpreted and often are. Not providing a reason prevents a semantic argument.

[xaur]

On Reddit when I want to include a reason for censorship I have to use regular comments. Semantically moderation discussion is "meta" to the thread and should be separate. And more generally, there can be more than 1 message in the "moderation stream". Even more generally, there can be two streams: one visible to all, and one to admins only.