Shift redundant code to #includes files

[mhpob]

This PR tries to move code redundant across programs into files that can be sourced by those programs. There were a few tradeoffs as there wasn't a "one size fits all" solution.

• Time-varying detection intercepts are of a different structure (time x receiver matrix) than the constant, "standard" versions (one number). I created a different likelihood for each.
• The tag-integrated model has an extra likelihood and extra data. I just kept these in the "master" model.
• Logistic decay has a slightly different likelihood Gaussian. I added a "logistic = 0" switch to go between them.

[benjaminhlina]

This looks great and really like how this removes redundancy in the code. I think the few areas where #inspect couldn't be used make sense given the specifics of what the model is doing.