Merge branch 'feature-refolding'

Incorporating improvements to FEC fitting using masks. Allows more
accurate fitting at low force with overlapping rips.

Also moving towards a less complex OO paradigm. Experiment objects
are becoming data structures with helper methods to do certain tasks.
This should simplify the addition of new functions, since these will
take trap data, fret data, or at most, the experiment object itself.

Open question: besides the usual metadata, should the experiment
data structures also be used to house results of calculations? Or is
it simply an object for transfering data around? The benefit of using
it as the single point for storing relevant info is that it will be
easier to use interactively.
ADD error handling to fec rip analysis

fec.Rips now handles errors in rip size calculations, and by
extension, so does fec.analyze() and fec.analyze_rips().

Also cleaned up some shell.py cruft.
Added progressbar and fitting improvements/fixes
Merge branch 'master' into feature-refolding

to get progressbar and other fitting enhancements
ADD progressbar.py; using in curvefit
Updating name imports
Re/moving stuff out of experiment.Pulling into fec.py
Renaming fileiO.file_matching kwargs
fplot.Figure.show() should now disply graph inline
NEW: db submodule using sqlalchemy