Took out most 'inoctave' changes.
Merge branch 'John's-branch'
Added loop
Added options to the model

The options are passed to model via a structure. Undefined options are
assigned default values.
Switched out 'disp' with 'println'

In octave, 'disp' doesn't display the output until the end of
computation unless you 'fflush(stdout)'. 'println' does just 'disp' for
MATlab.
1/2 new model

Added a while loop to find what x max goes to the sigma max, added two
user functions for eta_0 and a function for BCs, a check that our BC
function is far enough away from the shore, and a loop to find when we
need to swap methods.
Added Options, vectorized trapF
Merge branch 'John's-branch'
Merge branch 'Matt's-branch'