Participant Role selection via Profile in Event Registration is ignored (reopened CRM-3388)

Exactly the same issue as in CRM-3388 (http://issues.civicrm.org/jira/browse/CRM-3388)

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When a Profile with the Participant Role field is included in online Event Registration - and a value is submitted - that value should over-ride the default role for that event. Currently we ignore the profile field value and use default role.

1. Create profile and add Participant Role field
2. Link that profile to an event's Online Registration form
3. Register for event and select a role other than the default role

On the confirmation screen, the role is remembered correctly. When saving to database, default role is recorded.
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Tested on drupal.demo.civicrm.org; this bug is also present in 3.4.4 (as I found it on my site).