Changed Bukkit to Spigot

This pull request changes the server software from Bukkit to [Spigot](http://ci.md-5.net/job/Spigot/1456/).

**Server download location used**
* http://ci.md-5.net/job/Spigot/1456/

**Reason for pull request**
Spigot is a fork of Bukkit but with many memory and cpu improvements to ensure we are prepared for an active server.
For more info, visit the [Spigot Wiki](http://spigotmc.org/wiki/about-spigot)

**Proof of testing**
I ran spigot by simply replacing the craftbukkit.jar file with Spigot's .jar file. On the first boot, it asked for user input to confirm if I wanted to convert the save data.

This was odd, because the save data should already be converted. This may cause problems for the bot because the server bot can't provide user input without an admin being in the server. So this pull request should not be merged until either me or roboman are prepared to update the server.

Also, the server bot also needs to add another java argument when starting the server. This argument is `-XX:MaxPermSize=YM` where Y is the amount of memory in megabytes. Details about this argument can be found [here](http://spigotmc.org/wiki/changing-permgen-size/)

![convert question](http://i.imgur.com/0sbM7zQ.png)

![startup 1](http://i.imgur.com/VIOgceY.png)

![startup 2](http://i.imgur.com/cRg3htl.png)

Checksum of craftbukkit.jar

```
140199c346091a52045322fe0203f94b
```

**Related PR(s) and issue(s):**
* Issue #4 - This issue suggested we switch to Spigot.