Document that GST_PLUGIN_DEFINE macros use PACKAGE define. Fixes #559722.
Document that GST_PLUGIN_DEFINE macros use PACKAGE define. Fixes #559722.

PACKAGE is defined by autofoo. If people use something different, they might want to define it themself.

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