Apologies in advanced for cramming this all into one commit, but it's all fairly interdependent.

Removes the old tgstation database. It has been merged into the newer feedback database.
All mentions of the old database have been replaced with the new one.
This includes updating tgstation_schema.sql and dbconfig.txt.

Removes README feedback.txt as it is now covered by the new schema.

Removes the unused forum DB stuff, including forumdbconfig.txt.
Updates the config, including both config.txt and game_options.txt. Many options have been moved into the latter.
Updates configuration.dm to reflect these changes.

Removes the config var/feature_object_spell_system as it did nothing.
Updates text (TG -> /tg/station), and removes some old comments.
Merges motd help.txt and motd.txt.
Merge branch 'master' of github.com:tgstation/-tg-station into DB_cleanup
Updating the db table names as per erro's comment.
Merge pull request #92 from Petethegoat/DB_cleanup

Database & config cleanup