Added module Elm_gen.
Made creation of Elm_Gengrid_Item_Class more modular.
Added Elm_Genlist_Item_Type.
Added elm_genlist_item_append.
Added elm_genlist_item_prepend.
Added elm_genlist_item_insert_before.
Added elm_genlist_item_insert_after.
Added elm_genlist_selected_item_get.
Added elm_genlist_selected_items_get.
Added elm_genlist_realized_items_get.
Added elm_genlist_first_item_get.
Added elm_genlist_last_item_get.
Added elm_genlist_item_next_get.
Added elm_genlist_item_prev_get.