The "init. step" of couplers is a method now. Port to 0.6.

Also: re-initialize surface and ocean models at the very end of the
model setup to get rid of side-effects of this step.
Very minor cleanup. Port to 0.6.
Fix snow depth reset code. Port to 0.6.
PDD sub-intervals consistent with interpolation scheme. Port to 0.6.
Initialize variables in PDDMassBalance::step(). Port to 0.6.
-surface_given_period X should take an integer X. Port to 0.6.
Add -timestep_hit_multiples. Port to 0.6.

Also: refactor adaptive time-stepping code and document new adaptive time-stepping decision output. See #259.
IceModel::skip_counter() *returns* result.
Remove the "preliminary time-step duration" parameter.

The preliminary time-step itself was removed by 03c8571.
Update the Ross run scripts.

(There is no "preliminary" step now.)
Correct some doxygen comments.