Split dependency logic on the BuildCraft modules.
Config needs to be reset, if BuildCraft was disabled actively,
because now there are 3 BC modules to be taken account of
Provides a new configuration `mods` which can be used on Maven Artifacts. That way, we can install them without affecting them on runtime (less load time)
Put the optional tasks into `optional.gradle` where a install task is just a copy task and the deinstall task a delete task
Added maven local to the repositories, if for some reason somebody uses a local maven
The proper way to use gradle is to actually use the gradle.properties. It will be automatically read without using a self defined config slurper.
The gradle.properties adds additional convenient options e.g. regarding the VM options and parallel calculation or daemons
