Add f top command functionality. Resolves #71.

Gives the ability to see top Factions on the server sorted by certain criteria:
Balance: sorts by faction bank balance and all faction member balances.
Power: total power.
Land: total land claimed.
Online: members currently online.
Members: total members, online and offline.

Future criteria can be added of course.

src/main/resources/plugin.yml

@@ -92,6 +92,7 @@ permissions:
       factions.showinvites: true
       factions.seechunk: true
       factions.monitorlogins: true
+      factions.top: true
   factions.admin:
     description: hand over your admin rights
   factions.admin.any:
@@ -246,4 +247,6 @@ permissions:
   factions.monitorlogins:
     description: monitor join and leaves of faction members
   factions.claim.line:
-    description: claim in a line
+    description: claim in a line
+  factions.top:
+    description: sort factions