Config Update, Expression Settings, Plugin Update

We updated the config system. It now has easier mothods for getting
informations in different datatypes. We also added 4 custom settings to
some expression commands, e.g. max collect radius etc.
Furthermore, we created an interface "MinecartRevolutionPlugin" and two
classes "JavaMinecartRevolutionPlugin" and
"BukkitMinecartRevolutionPlugin". We had one class before, but with
"BukkitMinecartRevolutionPlugin" you have a Bukkit-Java-Plugin and a
MR-Plugin in one class.