FT_FILETYPE determines the filetype of many EEG/MEG/MRI data files by
 looking at the name, extension and optionally (part of) its contents.
 It tries to determine the global type of file (which usually
 corresponds to the manufacturer, the recording system or to the
 software used to create the file) and the particular subtype (e.g.
 continuous, average).

 Use as
   type = ft_filetype(filename)
   type = ft_filetype(dirname)

 This gives you a descriptive string with the data type, and can be
 used in a switch-statement. The descriptive string that is returned
 usually is something like 'XXX_YYY'/ where XXX refers to the
 manufacturer and YYY to the type of the data.

 Alternatively, use as
   flag = ft_filetype(filename, type)
   flag = ft_filetype(dirname, type)
 This gives you a boolean flag (0 or 1) indicating whether the file
 is of the desired type, and can be used to check whether the
 user-supplied file is what your subsequent code expects.

 Alternatively, use as
   flag = ft_filetype(dirlist, type)
 where the dirlist contains a list of files contained within one
 directory. This gives you a boolean vector indicating for each file
 whether it is of the desired type.

 Most filetypes of the following manufacturers and/or software programs are recognized
  - 4D/BTi
  - AFNI
  - ASA
  - Analyse
  - Analyze/SPM
  - BESA
  - Bioimage Suite (*.mgrid)
  - BrainSuite
  - BrainVisa
  - BrainVision
  - Curry
  - Dataq
  - EDF
  - EEProbe
  - Elektra/Neuromag
  - FreeSurfer
  - Localite
  - MINC
  - Neuralynx
  - Neuroscan
  - Nihon Koden (*.m00)
  - Plexon
  - SR Research Eyelink
  - SensoMotoric Instruments (SMI) *.txt
  - Tobii *.tsv
  - Stanford *.ply
  - Tucker Davis Technology
  - CTF
  - Yokogawa & Ricoh
  - nifti, gifti
  - Nicolet *.e (currently from Natus, formerly Carefusion, Viasys and Taugagreining. Also known as Oxford/Teca/Medelec Valor Nervus)
  - Biopac *.acq
  - AnyWave *.ades
  - Qualisys *.tsv
  - Mrtrix *.mif
  - MAUS *.TextGrid
  - Neurodata Without Borders *.nwb
  - PhysioNet *.hea and *.dat
  - NIRx *.tpl, *.wl1 and *.wl2