Include record count in 598 $c, conditional . in 506 $e

Include record count in 598 $c, conditional . in 506 $e

We might as well include the record offset in the 598 so that we can
track which record includes a given problem.

Also, according to Shuzhen, we only want to add a period at the end of
the 506 $e subfield in particular cases (like when it ends in a letter
or number; not with punctuation).

Signed-off-by: Dan Scott <dscott@laurentian.ca>