Makes a whole lot of changes

Adds some new tests
Improves plugin command handling by using one class for each command
Makes some changes to vehicle teleportation to support horses and pigs, but vehicle teleportation is still buggy and messy
Adds some more missing comments
Adds a wildcard permission and uses built-in permissions some places to avoid checking for three different permissions

src/main/java/net/knarcraft/stargate/BlockLocation.java

@@ -77,13 +77,17 @@ public class BlockLocation extends Location {
     }
 
     /**
-     * Makes a block location relative to the current location according to given parameters
-     * @param right <p></p>
-     * @param depth <p>The y position relative to the current position</p>
-     * @param distance <p>The distance away from the previous location to the new location</p>
-     * @param modX <p>x modifier. Defines movement along the x-axis. 0 for no movement</p>
-     * @param modY <p></p>
-     * @param modZ <p>z modifier. Defines movement along the z-axis. 0 for no movement</p>
+     * Makes a block location relative to the current origin according to given parameters
+     *
+     * <p>See {@link RelativeBlockVector} to understand better. modX or modZ should always be 0 while the other is 1
+     * or -1.</p>
+     *
+     * @param right <p>The amount of right steps from the top-left origin</p>
+     * @param depth <p>The amount of downward steps from the top-left origin</p>
+     * @param distance <p>The distance outward from the top-left origin</p>
+     * @param modX <p>X modifier. If modX = -1, X will increase as right increases</p>
+     * @param modY <p>Y modifier. modY = 1 for Y decreasing as depth increases</p>
+     * @param modZ <p>Z modifier. If modZ = 1, X will increase as distance increases</p>
      * @return A new location relative to this block location
      */
     public BlockLocation modRelative(int right, int depth, int distance, int modX, int modY, int modZ) {