unable to set specific email location types in profile on contrib forms

to reproduce:

• create or modify a profile. add an email field of a specific location type (e.g. home). add a second email of a different location type (e.g. work)
• configure the profile for use with a contribution page
• view the contrib page

you would expect to see the two email fields you've configured. instead, neither is exposed – only the hardcoded email above the profile.

this issue is related to CRM-15067, which would presumably address the problem by allowing an override of the hardcoded email address via the profiles. but in the meantime, the current behavior really limits one's ability to collect specific email addresses via a contrib form.