Don't depend directly on Vault in MoneyThingParser.

It turns out that the method reference on MobArena#getEconomy() in ThingManager is a tight enough dependency on Vault's Economy interface that it results in a NoClassDefFoundError if Vault isn't present.

By resorting to a more "naive" approach of resolving the Economy instance from the main plugin class on every parse call in MoneyThingParser, the NoClassDefFoundError is avoided along with the load/enable ordering issue that was fixed with the lazy-fetching in commit 2fcb20b2ae.

This reverts 2fcb20b2ae and partly 4c34a183c7.

Fixes #463

src/test/java/com/garbagemule/MobArena/things/MoneyThingParserTest.java

@@ -5,7 +5,9 @@ import static org.hamcrest.CoreMatchers.not;
 import static org.hamcrest.CoreMatchers.nullValue;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
+import com.garbagemule.MobArena.MobArena;
 import net.milkbowl.vault.economy.Economy;
 import org.junit.Before;
 import org.junit.Rule;
@@ -21,8 +23,11 @@ public class MoneyThingParserTest {
 
     @Before
     public void setup() {
+        MobArena plugin = mock(MobArena.class);
         Economy economy = mock(Economy.class);
-        subject = new MoneyThingParser(() -> economy);
+        when(plugin.getEconomy()).thenReturn(economy);
+
+        subject = new MoneyThingParser(plugin);
     }
 
     @Test