NickServ: DB Service for authentication and nick management

This initial implementation is not feature complete,
but is perhaps the minimum needed to be useful.
It does the following:
    * Allows users to authenticate
    * Registers authenticated users' nicks
    * Protects registered nicks from impersonation^

^ Important caveat: While it will force a nick change after a timeout,
it does not prevent the user from using the impersonated name within that time limit.
txircd.sql: Add some test data for donors
NickServ: implement logout
nickserv: Add GHOST command
nickserv: Implement ADD and DROP for nick management
nickserv: Implement NICKLIST
nickserv: Add a register command, which is disabled by default

We don't want register available in production, but it's very useful for testing.
Add a notice for the user when their nick is changed.
nickserv: Move around some commands and their aliases

* LOGIN is now an alias of IDENTIFY, instead of vice versa
* Added GROUP as an alias of ADD, since most nickservs call it that.
nickserv: Make registerNick stricter

Check if nicks are valid before registering
Renamed the unwieldy "ignoreAlreadyRegistered" to simply "quiet"
nickserv: Improve detection of forced nicks vs normal nicks
nickserv: Update default nick_timeout to 30
nickserv: Improve behaviour when the impossible happens
nickserv: After adding a nick, check if another user is already on that nick

This clears up a bug where a user that held a registered nick since before it was registered
could continue to hold it.
This bug doesn't occur in 0.2 as there was no way to register a nick without being the current holder.
nickserv: Prevent messages from nicks which are still being checked

NOTE: The 0.2 services stopped all but a small whitelist of commands.
Here we ONLY stop PRIVMSG. This is mainly because I couldn't figure out how to trigger an action
for commandpermission for ALL commands, as opposed to specific ones.
nickserv: Add full-stops to error messages
nickserv: Misc style fixes
nickserv: Add some more command aliases
nickserv: Improve command permissions to cover all commands
Merge pull request #35 from ekimekim/nickserv

Nickserv