formatting applied to most of the source code to tidy things up, and misc refactors

src/main/java/com/gmail/nossr50/placeholders/PartyIsMemberPlaceholder.java

@@ -5,6 +5,7 @@ import org.bukkit.entity.Player;
 public class PartyIsMemberPlaceholder implements Placeholder {
 
     private final PapiExpansion papiExpansion;
+
     public PartyIsMemberPlaceholder(PapiExpansion papiExpansion) {
         this.papiExpansion = papiExpansion;
     }