Add before and since filter to images

Add support for two now filter on the `images` command : `before` and
`since`. They work the same as the one on the `ps` command but for
images.

        $ docker images --filter before=myimage
        # display all images older than myimage
        $ docker images --filter since=myimage
        # display all images younger than myimage

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

contrib/completion/bash/docker

@@ -1104,6 +1104,11 @@ _docker_history() {
 _docker_images() {
 	local key=$(__docker_map_key_of_current_option '--filter|-f')
 	case "$key" in
+		before)
+			cur="${cur##*=}"
+			__docker_complete_images
+			return
+			;;
 		dangling)
 			COMPREPLY=( $( compgen -W "false true" -- "${cur##*=}" ) )
 			return
@@ -1111,11 +1116,16 @@ _docker_images() {
 		label)
 			return
 			;;
+		since)
+			cur="${cur##*=}"
+			__docker_complete_images
+			return
+			;;
 	esac
 
 	case "$prev" in
 		--filter|-f)
-			COMPREPLY=( $( compgen -S = -W "dangling label" -- "$cur" ) )
+			COMPREPLY=( $( compgen -S = -W "before dangling label since" -- "$cur" ) )
 			__docker_nospace
 			return
 			;;