Added abstract-like intro to modeling section
Some additional notes on figs
Added images dir with drawn figure 1a
Added excel file describing other models
Added Fig 1B to multi_cpt outline
Added notes on Fig 1C, validation of multi_cpt
Moved chunks of intro and outline around

Put the stuff on compartmentalization all in one place in the intro to
the compartmentalization section.
Massive rearrangement of content in stochastic_models chpt

* Created figures, notes subdirectories and put corresponding .rst files
  in there
* Fixed problem with plotting in translocation.rst
* etc.
Add and describe fig1B, comparison of 1C/MC Schwarz models

Also implement a number of cross references, add a brief/placeholder
methods blurb on how 1C and MC models were simulated.
Merge branch 'thesis'

Bring docs changes to thesis section into master with its new code.