_populate_channel_editor:
use app->sys_card_name instead of
e_mod_mixer_card_name_get _populate_channels:
select default channel or first one
_create_cards:
do not reselect card and channel
e_mixer_app_dialog_select:
cleanup, remove unused _find_card_by_name and _find_channel_by_name
_mixer_popup_cb_mixer:
do not modifiy current selection on popup