Messed up with the external data a bit...
A few changes to accomodate tiff files; not yet very stable though.
See lines 26-28 of processLandsat
sr2vi needs to be tested
The test datasets seem a bit corrupted, but that is not a bit problem for now.
hdf2ndvi should be deleted once sr2vi is stable.
Reverted sr2vi to overlay implementation, as it seems to be much faster than calc. It rolled back the tiff feature too... Use of stack and subset might solve the riddle.
tiff feature should work (assuming files are delivered as single bands in the archive and they order alphabetically se same way than in the hdf...)
Merge branch 'feature-tiff' into develop