gst/gsttagsetter.h: Can't cast ifaces to a class

gst/gsttagsetter.h: Can't cast ifaces to a class

Original commit message from CVS:
* gst/gsttagsetter.h:
Can't cast ifaces to a class
* libs/gst/net/gstnetclientclock.h:
* libs/gst/net/gstnettimeprovider.h:
* plugins/elements/gstfakesink.h:
* plugins/elements/gstfakesrc.h:
* plugins/elements/gstfdsink.h:
* plugins/elements/gstfdsrc.h:
* plugins/elements/gstfilesink.h:
* plugins/elements/gstfilesrc.h:
* plugins/elements/gstidentity.h:
* plugins/elements/gstqueue.h:
* plugins/elements/gsttee.h:
* plugins/indexers/gstfileindex.c:
* plugins/indexers/gstmemindex.c:
* tests/old/examples/plugins/example.h:
Fix more gobject macros: obj<->klass, GstXXX<->GstXXXClass