This renames the input sftfilepath to sftfilepattern and adds
documentation on how that should be used, i.e. a colon separated list of
wildstring or exact matches. In globbing for all matches, the colon
split is added in. sftfilepath is still used by `Writer` since
an exact path is known.

Note - There appears to be some difference between the integration plot
and the output value. This may be related to the Riemann sum issue in
emcee itself. Eventually, we should have a case where we calculate the
Bayes factor directly and compare this.