def projections_path(path=Ellipsis):
if path is Ellipsis: return config['<STR_LIT>']<EOL>else: config['<STR_LIT>'] = path<EOL>
projections_path() yields the projections path currently being used by neuropythy. This is
  equivalent to projections_path(Ellipsis).
projections_path(path) sets the neuropythy projections path to be the given argument. The path
  may be either a single directory, a list of directories, or a :-separated list of directories.

Before returnings, the map projections mapping stored in neuropythy.map_projections is updated
to include all map projections found in the given directories. Old map projections found in the
previous projections-path directories are discarded; though map projections found in
neuropythy's lib directory are always kept (but may be overwritten by projections in the path
with the same name)

In order to be included in the returned mapping of projections, a projection must have a
filename that matches the following format:
  <hemi>.<name>[.mp | .map | .projection | <nothing>].json[.gz]
For example, the following match:
  lh.occipital_pole.mp.json    => map_projections['lh']['occipital_pole']
  rh.frontal.json.gz           => map_projections['rh']['frontal']
  lh.motor.projection.json.gz  => map_projections['lh']['motor']