Change Approved/ApprovedYear Logic (curious case of Amikacin)

[grishagin]

TODO Summary:

1. approvedYear should use the earliest Marketed date NOT the earliest ApprovalRx date.
2. Drugs@FDA listed drugs that are marked "Discontinued" AND with a Federal Register determination should be marked as Approved (Having an NDA reference is almost always superior to an ANDA reference)
3. For older drugs, Pharm Manu Encycl consistently provides the most accurate start marketing date.

SEE ALSO:
https://www.wrike.com/open.htm?id=185768500

Justification

http://archive.gao.gov/d24t8/141456.pdf (page 59) provides NDA numbers and Dates of approval for NDAs from 1976-1985

From this list, I decided to check the data on an older drug:

NDA 50495 Amikacin sulfate 7/12/76

This drug is listed in Drugs@FDA
https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=050495

HOWEVER, Drugs@FDA lists the marketing status as "Discontinued", and no submissions are listed, so no date for the application is given.

IMPORTANTLY, in products.txt in the "ReferenceDrug" column, NDA 50495 is marked with the comment:
"**Federal Register determination that product was not discontinued or withdrawn for safety or efficacy reasons**"

Now, the Pharm Manu Encycl correctly lists the approval year for this drug at 1976.