Add existing activity fields to a profile

From the profile in place edit CRM-9840, being able to add existing fields to the profile (the interface will be inspired by the webform civicrm one)
1) list of all available fields with checkboxes. You can add several fields in one go
2) fields are grouped logically instead of one big list
eg for contact: (standard fields, address fields, email fields, phone fields, custom set A, custom set B...)