Refactored fastaq-to-fasta.py to default output to sys.stdout

Updated interleave-reads output listing to point to the proper place

refactored load-graph output listing to drop an else clause
(may have blatantly copied from mr-c here)

removed debug string from abundance-dist that somehow made it into
the last commit

refactored make-initial-stoptags test generate test data from
load-graph.py to reduce payload size of test_data directory
note: this assumes load-graph will work
removed some extraneous files in the test-data directory after
refactoring make-initial-stoptags test