- Use of 'name' attribute for files and filesets has been simplified.

  So far, it has been the case that 'path' denoted the *directory* where
  that fileset or file resided. Then, 'name' would complement that path by
  referring to the name of the file created, or the directory under which the
  fileset would be instantiated. At the same time, 'name' is predominantly
  used as a unique identifier. This creates an interesting clash.
  From now on, 'name' is *only* used as an identifier. And 'path' is expected
  to point to the actual file, or the root directory of the fileset to be
  created.

- Added grammar and code support for 'path' values that start with a
  variable and end with a string (e.g. "$dir/bigfile")

- Refactored code to always obtain the fileset path through fileset_getpath
  (fileset.h). Simplifies maintenance greatly.