Add support for Bukkit's version safeguard.

Finally got shading working with gradle thanks to AbrarSyed =)
This should fix a bunch of plugins that check for a package version.

ex. PortableHorses does the following to get server version

String packageName = this.getServer().getClass().getPackage().getName();
String version = packageName.substring(packageName.lastIndexOf('.')+ 1);

This will now work and properly return a valid package version such as
"v1_7_R1".
Merge branch 'master' of https://github.com/MinecraftPortCentral/Cauldron