Pull in LBHB-specific code

[svdavid]

Add folder? Or add to tools:

Definitely include:
uri.py
recording.py. (migrate call to adjust_uri_prefix and recording name h
epoch.py
signal.py

Move to nems_db.nems_lbhb?
utils.py -- anything useful for core signal/recording stuff?
db.py
preprocessing.py
xforms.py
xform_helper.py
initializers.py
plugins/*

Pick useful parts, move to nems_lbhb?
plots
analysis
fitters
configs
cross_validation.py
priors.py
metrics
modelspec.py
segmentors.py