CraftTweaker Integration

Removed all stuff related to networking, thread and file IO because those were entirely a stupid idea and really don't fit into CraftTweaker. I should never have made that. (Also they cause security problems)

Modpack devs wishing to add update checks or other network related stuff should just make their own mods instead, or look for mods that has the feature (CustomMainMenu, MPUtils, etc) * Added a simple class that just logs raw strings to a file.