+func: easier debugging of Workflows

SimpleWorkflows compile their code with a filename (consisting of
their class name and id) instead of simply `<string>`
reliability: force little-endian-ness of index data

When serializing/deserilizing index data for storage using
`struct.pack()` or `struct.unpack`, force little endian byte order
for compatible use of resulting files on systems with different
native formats.
admin: strip EOF char from VERSION.txt in setup.py