Add self arg to virtual funcs in models.core
Tests for changes in tBid concentration
Added .tsv to .gitignore
Add support for fitting multiple timecourses simultaneously

This involved a series of changes:

- in nbd_mcmc_pysb_run, arguments for the nbd_sites and nbd_observables have to
  be able to accept lists, which are implemented as hyphen-separated strings,
  e.g., nbd_sites=c3-c62 nbd_observables=iBax-Bax2
- in nbd_mcmc_pysb, functions that handle plots for fitting or calculation of
  the likelihood function were changed to accept lists of sites and
  observables.
- submit_jobs.py had to change the arguments passed at the command line from
  nbd_site to nbd_sites, etc.
- util/report.py had to be modified to work with figures created in a
  non-interactive fashion.
Fix unlinking bug in util/report.py
Remove nbd_test_convergence.py

Probably don't need this script anymore (it just loaded MCMC pickle
files and then printed out the convergence criterion for each) because I
have the reporter code now.
Remove nbd_manual

This is assuredly obsolete by now, as there are many new models and also
a systematic approach to fitting.
Deleted unnecessary file lsf.py