gst/videocrop/gstvideocrop.*: Handle packed YUV formats (UYVY, YUY2, YUYV) separately; also, fix passthrough mode; la...

Original commit message from CVS:
* gst/videocrop/gstvideocrop.c: (gst_video_crop_class_init),
(gst_video_crop_init),
(gst_video_crop_get_image_details_from_caps),
(gst_video_crop_transform_packed_complex),
(gst_video_crop_transform_packed_simple),
(gst_video_crop_transform), (gst_video_crop_transform_caps),
(gst_video_crop_set_caps),
(gst_videocrop_clear_negotiated_caps_locked),
(gst_video_crop_set_property):
* gst/videocrop/gstvideocrop.h:
Handle packed YUV formats (UYVY, YUY2, YUYV) separately; also, fix
passthrough mode; lastly, clear negotiated basetransform caps when
the cropping changes in order to force renegotiation.