Minor pylint-suggested fixes
add-team: Disallow empty arguments
Merge remote-tracking branch 'origin/master'
SQL: Use 'CHAR(32)' to identify all file collections

For some reason, I had VARCHAR(255) for some of these.  Of course, when
you collect a set of files with 'db.migrate', you get a 32-character MD5
checksum back out, so all file collections should be 'CHAR(32)'s.
Resurrect 'ppaml evaluate'

'ppaml evaluate' got punted when we switched to SQLite a while back, but
it’s now been restored.
Submit: Use database query functions from the previous commit

In the previous commit (2cdb6f4), I added some code to 'db' that allows
grabbing runs by run ID or tag.  I modelled it on the code in 'submit'
for doing the same; this commit merges the two, eliminating the
duplication between the modules.
Submit: Annotate a BUG and a TODO