#97. Improved drupalgap_entity_render_content() by iterating over the items delta values and running through each through the theme() layer. Improved text_field_formatter_view() by iterating over items and building each into a render object and then returning the collection. Added the image module, image_field_formatter_view() and taxonomy_field_formatter_view().  Adjusted the drupalgap.services.* (comment, taxonomy_term, taxonomy_vocabulary) retrieve success call back functions to call drupalgap_entity_render_content() so the entity's content will be assembled. Removed remnants of drupalgap.comment, drupalgap.taxonomy_term, drupalgap.taxonomy_term_edit.