Merge branch 'release/0.21' into develop
bump develop version to 0.22.0-dev after releasing 0.21
always load rels-ext as rdf; don't pull and checksum content datastream just to see if it has been changed
minor cleanup
initial version of a script to validate checksums across fedora and story last fixity check in rels-ext [#58717416]
update validate checksum script with logic to generate and load a config file with encrypted fedora password [#58717416]
tweak cryptutil so it's usable without django
configure validate-checksum script to be installed via setup.py [#58717416]
preliminary documentation for validate-checksums script; cleaner argparse requirement handling [#58717416]
clean up script output so only errors and end summary are printed in quiet mode [#58717416]
fix missing include in setup.py (checking for py2.7 / argparse)
preliminary support for email reporting functionality [#58717536]
preliminary report output to go in email text [#58717536]
command-line and config file options for email; logic to actual send the email [#58717536]; fix so command-line args override config file
make email from address a required parameter, via command line or config file [#58717536]
add more documentation for using the validation script [#58717536]
add better error-handling to fedora API calls when validating, and include any errors in the email report [#58717416]
add error-handling and reporting for cases where object has malformed rels-ext [#58717416]
fix count of rels-ext errors reported in script summary
add logic to store detailed checksum report as premis fixity event for objects with a premis datastream [#58717760]