[CONFIG][BACKEND] Adds PR announcing to the game.

Adds a C# program that allows you to parse GitHub Pull request opening
notifications sent to an IRC and display them in-game.
Adds authentication to the world/Topic() procs, allowing you to easily
and securely input data into the game (EXPORT DOES NOT REQUIRE IT!)
updates the code
Removes an useless message_admins.
Removes a redundant message part.
Adds a separate config option for enabling comms/API
Makes the nag message not activate if comms are not enabled

This nag message should only come up when something has gone horribly
wrong.
Revert "Adds a separate config option for enabling comms/API"

This reverts commit 19d46a7084544ae28127cc302c1941f4290e6be3.
oops, mistyped there
Config_key now starts out uncommented in config

I wonder how much stress am I putting on Travis with my minutely
commits!
Adds a bit more sanitization to the PR announcer

Shouldn't be parsing any HTML tags inside the PR name.
huge update

Makes the announcer better in every aspect (less bugs, less fun, more
merging announcement capability)! Also makes it require *just* .Net 4.0
instead of 4.5.
Adds the option for players to disable the PR announcements.
Updates a bunch of things

Branch info no longer included in PR message. Exception handling
everywhere. Retrying connection is now a feature, also it won't crash
anymore if the server goes down for some reason when it tried to send.
Refactored code.
Removed 54331321314314135 counts of /client/proc/fun()
Merge pull request #3418 from VistaPOWA/pr_announce

[CONFIG][BACKEND] Adds PR announcing to the game.