Use Maven, add missing Command Nodes, load player skills asynchronously to not lag the server

Like I said, most Bukkit plugins use Maven. This allows developers to easily contribute and modify the code, and for a build server to create development builds.

All major Java IDEs ship with Maven support: Eclipse for Java Developers (NOT EE, but m2e can be installed for EE), IntelliJ IDEA, Netbeans, whatever.

Quests is a Maven project, but does not have a Maven repository, so it is easier to ship the JAR than to `mvn clean install` Quests into your local repository. Same with MCCore.

`mvn clean package` or `mvn clean install`, using the command line or your IDE's Maven integration to build. The JAR is outputted in `target/`. For detailed build instructions for Eclipse, see the Bukkit Plugin Tutorial: http://wiki.bukkit.org/Plugin_Tutorial#Deploying_your_Plugin

I also fixed some missing command nodes that were present in the configs but not in the code in order to get this to compile, and implemented asynchronous player loading in order to not lag the server.

**Before:** http://aikar.co/timings.php?url=7577059
**After:** http://aikar.co/timings.php?url=7577360