include MARA classification

[irenne]

closes issue #19

[JohannesHoehne]

update this description, mentioning that the dependencies can be downloaded with
bbci_import_dependencies('MARA')

[BenjaminBlankertz]

The requirement to have the required files in the path is not so nice. I think they should be stored, e.g., somewhere below [BTB.DataDir, '/bbciFile'] and then you load them accordingly
load( fullfile( BTB.DataDir, 'bbciFile', 'MARAtrdata', 'fv_training_MARA') );

In the demo, it should be checked whether the required files exist. If not issue an error message that explains where to store the files and where to get them.
(Btw. in the ZIP file, there are these auxiliary MACOSX files. Would b nice to remove them from the archieve.)

The demo looks very good!

[JohannesHoehne]

try
loadData = load(fullfile(BTB.Dir, 'external', 'mara', 'inv_matrix_icbm152.mat'))
L = loadData.L
clab = loadData.clab
catch
error(sprintf('could not load dependencies of MARA. \nMake sure that you have have successfully downloaded the requested files with \n\n> bbci_import_dependencies(''MARA'') '))
end

[JohannesHoehne]

@BenjaminBlankertz : The MARA data can be downloaded with the bbci_import_dependencies('MARA')

However, saving these directly into the BTB.DataDir may be problematic as the startup script will be executed before defining the DataDir... Therefore, I vote for leaving the MARA data in the BTB.Dir/external/mara ...

[BenjaminBlankertz]

Ok. From my side, the issue can be closed.