Changed environment, getters, tmp folder manager.

Changed the development environtment to mimic a real development enviroment with node_modules, therefore the node_modules aren't ignored at the moment. Also added the getters within the Slidevs object again, for getting the right data in the build functions. New: Temporary folder manager. Slidevs creates a new hidden folder on start to paste all build code in, in order to start the slidevs.