Refactor ctffind4 pipeline

[jpellman]

Refactoring the ctffind4 pipeline hasn't been a high priority because classic Appion's performance is adequate for this tool. Now that the motioncor2 pipeline is refactored, however, we should turn our attention to ctffind4.

[jpellman]

While I'd like to do this sooner rather than later, I'm not sure it should actually be high priority. We can continue running the legacy Appion ctffind4 pipeline in an enroot container alongside the refactored motioncor2 pipeline pretty readily. Josh has recently expressed more interest in getting ctffind5 to run with our current myamiweb/Appion/Leginon deployment, and it might make more sense to prioritize getting that to work within a classic Appion container (i.e., we should favor new features to refactoring here).