Updated some incompatibilities #6
Description
Handled the case where the filename is not passed into mha_read_volume, which caused an error in calling mha_read_header with an undeclared variable (filename)
fopen doesn't seem to need the filename to be transposed (and Octave hates it)
if fopen doesn't work with big/little endian cues, open it and hope for the best
Functions require an "end" before the next function definition
Added *.mhd to file types to open
Works the same for both Matlab and Octave
Fixes are attached