ItemsToSolr export process still identifies some Gov Docs numbers as "other" call numbers

[jthomale]

After fixing #11, there are still some instances where Gov Docs numbers on an item (or bib) in an 099 field are not correctly being identified as Gov Docs numbers even though there is an 086 on the bib record.

This is happening when the string in the 099 doesn't exactly match the string in the 086, which could happen for a couple of reasons.

1. In some cases it appears there's a typo or simple formatting difference between the 086 and 099--one is partially lower case and the other isn't, or one includes a period at the end and the other doesn't.
2. In other cases, there are multiple items attached to the bib record and the 086 field attempts to accommodate all of the items (using a string indicating a range or something similar). In those cases, none of the individual 099s match the 086 exactly.

Normalizing the two numbers before comparison would help with some instances of number 1, but number 2 is a little more difficult. Maybe comparing the numbers up to a certain point? I'd hoped to be able to get away with not doing more strenuous parsing of sudoc numbers for the comparison.

In at least one case I've also seen an item with multiple 086s in the bib record with different sudoc numbers in each 086.

[jthomale]

Sudoc numbers have a very particular format. It would probably not be too difficult to detect whether something is a sudoc number based on that formatting. The logic could be: if there's an 086 present on the bib record or item record, and if the "other" call number in question looks like a sudoc number, then it's a sudoc number--otherwise it's an "other" call number.