Resetting fitter states if references to their AAMs/CLMs are changed?

[jalabort]

Shiyang run onto a bit of weird problem today. He has an algorithm that given an AAM produces a new AAM whose shape/appearance means and components are a modified version of those of the original one. His idea was to create a Fitter around the first AAM and then simply replace the AAM with the AAM output of his algorithm (fitter.aam = new_aam). He was expecting the fitter to work as if it was created using the new AAM which did not hapend due to the fitter having some inner state that was computed on construction. While this is not a massive problem (since he can always build a new fitter...) I can see why he though that would work... Since fitter.aam is public, maybe we should put a setter on it so that fitter._set_up is automatically called if the aam is reset... Sensible?

[patricksnape]

Sounds pretty sensible to me. Either that or make the AAM private.