add check for setting pad_get and pad_chain functions on wrong type pads.
add check for setting pad_get and pad_chain functions on wrong type pads.

Original commit message from CVS:
add check for setting pad_get and pad_chain functions on wrong type pads.

cablelabs/gstreamer,mparis/gstreamer,ahmedammar/platform_external_gst_gstreamer,drothlis/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,Lachann/gstreamer,magcius/gstreamer,ensonic/gstreamer,krieger-od/gstreamer,lovebug356/gstreamer,ylatuya/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,cfoch/gstreamer,ensonic/gstreamer,surround-io/gstreamer,krieger-od/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,ahmedammar/platform_external_gst_gstreamer,mparis/gstreamer,ensonic/gstreamer,jpxiong/gstreamer,ylatuya/gstreamer,ensonic/gstreamer,ylatuya/gstreamer,shelsonjava/gstreamer,cfoch/gstreamer,Lachann/gstreamer,krichter722/gstreamer,cablelabs/gstreamer,mrchapp/gstreamer,krichter722/gstreamer,lovebug356/gstreamer,krieger-od/gstreamer,mrchapp/gstreamer,drothlis/gstreamer,collects/gstreamer,drothlis/gstreamer,Distrotech/gstreamer,mrchapp/gstreamer,centricular/gstreamer,Lachann/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,jpakkane/gstreamer,surround-io/gstreamer,Distrotech/gstreamer,magcius/gstreamer,lubosz/gstreamer,cfoch/gstreamer,jpxiong/gstreamer,cfoch/gstreamer,magcius/gstreamer,justinjoy/gstreamer,justinjoy/gstreamer,Lachann/gstreamer,cfoch/gstreamer,Distrotech/gstreamer,StreamUtils/gstreamer,mparis/gstreamer,Distrotech/gstreamer,drothlis/gstreamer,cablelabs/gstreamer,collects/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,ylatuya/gstreamer,lovebug356/gstreamer,cablelabs/gstreamer,justinjoy/gstreamer,centricular/gstreamer,mparis/gstreamer,ahmedammar/platform_external_gst_gstreamer,jpakkane/gstreamer,magcius/gstreamer,lovebug356/gstreamer,krieger-od/gstreamer,cablelabs/gstreamer,ylatuya/gstreamer,ensonic/gstreamer,centricular/gstreamer,krieger-od/gstreamer,lubosz/gstreamer,drothlis/gstreamer,jpakkane/gstreamer,Lachann/gstreamer,justinjoy/gstreamer,collects/gstreamer,Distrotech/gstreamer,ahmedammar/platform_external_gst_gstreamer,StreamUtils/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,lovebug356/gstreamer,centricular/gstreamer,magcius/gstreamer,surround-io/gstreamer,ahmedammar/platform_external_gst_gstreamer,jpakkane/gstreamer,mparis/gstreamer,shelsonjava/gstreamer,collects/gstreamer,mrchapp/gstreamer,krichter722/gstreamer,collects/gstreamer,mrchapp/gstreamer,justinjoy/gstreamer