Better debugging on CIF file read in. (#356) Issue #355 indicates that errors in mmCIF parsing are not well handled. This commit attempts to fix that in two ways. The first is to add a 'from extension' fallback if the from-contents parser doesn't like it. We assume that if you're naming it xyz.pdb, you want it parsed as a PDB. The second is to print the diagnostics report for mmCIF files to the tracer -- this is what's being used to autodetect mmCIF format, so better transparency of what the failure issue is would be warranted.