Bug 1075470 - Met "undefined method `platform' for nil" error when creating application of download cartridge.

Ignore cartridges that are not found in implicit_application_overrides, for same platform verification.

Change call from 'first' to 'find' when looking up cart.

Fix wrong name attribute for cartridge.
Merge pull request #4954 from UhuruSoftware/master

Merged by openshift-bot