RFC to add ignore user feature

[root-goblin]

Addressing: #568 and #734

MVP Requirements

• Add configurable list of ignore-users to data::config::Server, reference: configuration option for Monitor.
• Implement message filtering on history load (reference buffer::ServerMessage.smart for implementation)

Nice To Have

• discard filtering mechanism + configuration item
• new command::Kind and related parsing

[andymandias]

Here's my suggestion for how to split this up into bite sized chunks. First these two:

• Add configurable list of users to ignore, similar to the configuration option for Monitor.
• Use the configuration to discard or hide messages. Smart filtering is a good reference for hiding messages. My personal preference would be hide, but I can see an argument for both.

That will provide the base functionality (which can be accessed on the fly via configuration reload) with what I expect will be the least amount of work. Then, once that's completed, decide whether you want to do either of the following:

• Add a configuration option to allow for whichever ignore behavior you did not already implement.
• Add a new command (this is the task I expect will require the most effort).

[root-goblin]

I took at look at command parsing and it does look like it will require a lot of moving pieces. I'll stick with your suggestions and hit up the two low hanging fruit first.

My personal preference would be hide, but I can see an argument for both.

I've had some conversations with other users, and the preference does seem to be toward hiding.