phpdoc corections
Correctly merge raw_properties into vars for `edit_field_html`
Add new admin_field_html method for the Users > Profile Fields screen in wp-admin
Mark base field type methods `edit_field_html` and `admin_field_html` as abstract
Removing `BP_XProfile_Field_Type_Programmatic`

I can’t remember the use case
Don't mark admin_field_html as abstract yet to avoid breaking everything until the classes have this method implemented
abstract methods can't contain a body, yo.
Remove all the Users > Profile Fields HTML code. We're going to use the new `admin_field_html` method for this.