Now each server server has an maven module which implements changes to
the default behavior within the "core" gameserver module. This allows to
keep multiple server versions without the need of several branches and
with little code duplication.
This commit modularizes the maven project into several modules:
- l2jserver2-common: common sources for both login and gameserver
- l2jserver2-gameserver: the game server
- l2jserver2-loginserver: the login server
- l2jserver2-tools: refactored src/tools/java soure folder