Move core plugins out of core. I don't mind fdsrc/fdsink going back into the core...

Move core plugins out of core.  I don't mind fdsrc/fdsink going back into the core; they were just disabled there, so

Original commit message from CVS:
Move core plugins out of core.  I don't mind fdsrc/fdsink
going back into the core; they were just disabled there, so
I moved them.  Some of this stuff could (should) be deleted.
* gst/oldcore/Makefile.am:
* gst/oldcore/gstaggregator.c:
* gst/oldcore/gstaggregator.h:
* gst/oldcore/gstelements.c:
* gst/oldcore/gstfdsink.c:
* gst/oldcore/gstfdsink.h:
* gst/oldcore/gstfdsrc.c:
* gst/oldcore/gstfdsrc.h:
* gst/oldcore/gstmd5sink.c:
* gst/oldcore/gstmd5sink.h:
* gst/oldcore/gstmultifilesrc.c:
* gst/oldcore/gstmultifilesrc.h:
* gst/oldcore/gstpipefilter.c:
* gst/oldcore/gstpipefilter.h:
* gst/oldcore/gstshaper.c:
* gst/oldcore/gstshaper.h:
* gst/oldcore/gststatistics.c:
* gst/oldcore/gststatistics.h: