CiviMember Import incorrectly requires Contact ID field / does not handle contact matching on contact ID

According to the instructions at the beginning of the CiviMember Import Wizard, you can match Membership recors to contact records using Contact ID, or External ID, or the regular Contact Matching Rules.

We need to make sure that all three options are working and that the form rule requires that the mapping selections support ONE of the three possible match scenarios:
1. Contact ID column is mapped
OR
2. External ID column is mapped
OR
3. Column(s) to be used for matching by "rule" are mapped (e.g. first, last, email address w/ the current contact matching rules)

NOTE: When the reworked Duplicate Matching Rules code is integrated into this code, the formRule for scenario 3 above would be use use the configured default "strict match" rule for the selected Contact Type (e.g. the selected "contactType" radio button in Upload.php).

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However, upon clicking 'Continue' at step 2, I am given the error that

"Missing required contact matching field: Contact ID."

In 2.0.14017 (via SVN checkout), 'Contact ID' is not even offered as an option in the Matching CiviCRM Field drop-down. (This does not appear to be the case on the demo, however the 'required field' error is still triggered on the demo when Contact ID is not selected.) But more importantly, the field should not be required at all.