change how OP is handled

[eahenle]

Currently, OP for aligning r_c to p' is done in two steps, allowing greater error propagation (especially if p', q_c, and r_c are not the exact same geometry). This is done because the mapping \phi needs to be chosen with the assistance of OP.

Refactor so that once \phi is selected, the final OP is performed using \phi and \theta together.

[eahenle]

actually, change code so that OP is performed on inverse(\theta) \compose \phi

[eahenle]

piggyback issue: the subsets for geometric center alignment are incorrect. replacement is aligned to full p', but needs to be subset of p' isomorphic to q'