configure.ac was changed to work with new versions of OpenCV 3.X.
A new include is added gstopencvutils.cpp because it contains
the previous. This keeps compatibility with 2.4.
https://bugzilla.gnome.org/show_bug.cgi?id=760473
Since commit 45ca8876b2 nobody is using
gst_opencv_get_ipl_depth_and_channels() or
gst_opencv_parse_iplimage_params_from_structure(). Remove this dead
code.