GDF - update V1.25

[Alois Schlögl <alois.schloegl ***AT***tugraz.at>]

The description of GDF-Format has been updated (V1.25). It is available 
at:
http://www.dpmi.tu-graz.ac.at/~schloegl/matlab/eeg/gdf4/TR_GDF.pdf

The difference is that the sampling rate is now stored the beginning of 
the Eventtable. This is necessary for storing pure event information in 
GDF. In a file without any channels, the sampling would not be defined.


Alois