docs: make explicit that the caps passed to gst_base_src_set_caps() are 'tranfer none'
docs: make explicit that the caps passed to gst_base_src_set_caps() are 'tranfer none'

https://bugzilla.gnome.org/show_bug.cgi?id=733741

centricular/gstreamer,jpxiong/gstreamer,centricular/gstreamer,mparis/gstreamer,mparis/gstreamer,StreamUtils/gstreamer,centricular/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,jpxiong/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,StreamUtils/gstreamer,krichter722/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,mparis/gstreamer,centricular/gstreamer,mparis/gstreamer,mparis/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,StreamUtils/gstreamer