mod inclusion whitelist

Suggested by alterNERDtive, and by some other people here and there.

The new gui should allow specifying entries (ids, basically), right below the exclusion list and in the "Advanced Settings" section, to force SPC to include any mod that matches any entry in said list.

changed milestone to %Version 5 - Peauty!!11!

added Feature label

assigned to @Griefed

Add a toggle between whitelist or blacklist taking priority

closed