Dropped FileMappings as they don't appear that useful. Anything that performs a copy is better off stating the directory where things are copied to rather than a description of the copy operation. Can't think why FileMappings would be useful to other tasks. The assets tasks consequently returns a folder of where assets were copied to.

Modified PathMappings to just the tuple and defined its type as PathMapping. Expressing a Seq[PathMapping] throughout code is reasonable and meaningful without being verbose (whereas a Seq[(File, String)] is meaningless and verbose).