Seasonal recruitment / g3_parameterized(... by_step = TRUE)

[lentinj]

@mmrinconh 's model has seasonal recruitment, i.e. both rec.1990 and anch.rec.sd should be per-step. This seems a not-unreasonable thing to want.

There's lots of ways to achieve this, but the easiest would probably be:

g3a_renewal_normalparam( . . . factor_f = g3_parameterized('rec', by_year = TRUE, by_step = TRUE) . . . )

...or possibly the more flexible:

g3a_renewal_normalparam( . . . factor_f = g3_parameterized('rec', by_time = c('year', 'step')) . . . )

[lentinj]

Nah, the by_time option is silly, and creating a migration for no reason.