Use namedtuple for field infos
Remove pointless conditions
Improve empty array checks
Use power operator
Use comprehensions and sums
Implement get_average and get_deviation in terms of get_aver and get_devi
Move get_aver
Improve get_aver
Use get_aver in get_differential and get_devi
Separate song title from echonest
Separate artist from echonest stuff
Separate file path from echonest stuff
Remove last usages of the songNamespace variable
Move the echonest table schema to data_mining.py
Move echonest field infos to data_mining.py
Don't use star imports with config

This ensures that we are always editing values that the whole program
can see.
Pass the table to use to the importer subprocess

It's a different process, so it doesn't inherit anything we've set.
Do imports and set the api key when we are actually going to start getting features

Fixes first-run and uses the right config values.
Don't delete the mood namespace
Don't delete the feature table