Change Server.getName() to return "MCPC+" and not "Craftbukkit"

As of Yesterday, September 1st, 2013, [Pex no longer requires Server.getName()](https://github.com/PEXPlugins/PermissionsEx/commit/be926c2b6c58ffbe064fcac3bdb836ea4f96ce9a) to return the String "Craftbukkit" to function, [and it's been in BukkitDev since then](http://dev.bukkit.org/bukkit-plugins/permissionsex/files/19-permisions-ex-v1-20/). This means that there is **no reason** that MCPC+ shouldn't follow [Bukkit API guidelines](http://jd.bukkit.org/rb/apidocs/src-html/org/bukkit/Server.html#line.53) on Server.getName().