Party GUI and party now handle leaders/promotion

Please note that leader status is signified by the negative party number.
Currently, our display still shows the negative number so that we may
determine it quickly for testing purposes; we need to change that before
release.
Added promotion to GUIParty and PartyManagerServer

Merge branch '1.7.2' of https://github.com/jaltekruse/WhatEverYouWantMinecraft into 1.7.2

Conflicts:
	java/emd24/rpgmod/party/PartyManagerServer.java
Merge branch '1.7.2' of https://github.com/jaltekruse/WhatEverYouWantMinecraft into 1.7.2
OnPlayerLogout working, affects Party Heal & GUI