PIE XML Feed Cake Shell

Summary:
Refs T1510: PIE XML Feed Cake Shell

Also fixed arc and arc lint config's

Test Plan:
generate a CSV according to the instructions in the README. Process it. And validate it against its specified schema.

http://www.bazaarvoice.com/xs/PRR/PostPurchaseFeed/5.6

Reviewers: gwarner, #everyone

Reviewed By: gwarner, #everyone

Subscribers: gwarner

Maniphest Tasks: T1510

Differential Revision: https://dev.blendtec.com/D975