FIX Cardinal points, COSMITS
ENH montage loading for hpts; RM fids from montage
RM fiducials from test_montage
FIX montage args

Removed fids from args
FIX test.hpts
ENH: centralize polhemus data readers

Fixed their references
ADD test for polhemus readers
Remove specific hsp/elp reader

This parsing is easily done with np.loadtxt. Code updated accordingly.