nanshe_learner: Changed mechanism of determining path to the nanshe_learner executable to queue up subprocess calls in generate_neurons_blocks.
HDF5_serializers: Corrected case of unicode filename. Also, corrected a bug with region refs that were gotten to through an External Link.
nanshe_learner: Turned off using external links to the input file for the blocks case. Presently, copies the input file data into the output file, which appears to work.
nanshe_learner: Added debug output for merging the results from blocks in generate_neurons_blocks.
test_nanshe_learner: Added another test for main from nanshe_learner. This fixes #122.