Remove AppSrc/AppSink that are moving to -base. Partially fixes #564421

Remove AppSrc/AppSink that are moving to -base. Partially fixes #564421

Original commit message from CVS:
* configure.ac:
* docs/plugins/Makefile.am:
* docs/plugins/gst-plugins-bad-plugins-docs.sgml:
* docs/plugins/gst-plugins-bad-plugins-sections.txt:
* docs/plugins/inspect/plugin-app.xml:
* examples/Makefile.am:
* examples/app/.cvsignore:
* examples/app/Makefile.am:
* examples/app/appsink-src.c:
* examples/app/appsrc-ra.c:
* examples/app/appsrc-seekable.c:
* examples/app/appsrc-stream.c:
* examples/app/appsrc-stream2.c:
* examples/app/appsrc_ex.c:
* gst-libs/gst/Makefile.am:
* gst-libs/gst/app/.cvsignore:
* gst-libs/gst/app/Makefile.am:
* gst-libs/gst/app/gstapp-marshal.list:
* gst-libs/gst/app/gstappbuffer.c:
* gst-libs/gst/app/gstappbuffer.h:
* gst-libs/gst/app/gstappsink.c:
* gst-libs/gst/app/gstappsink.h:
* gst-libs/gst/app/gstappsrc.c:
* gst-libs/gst/app/gstappsrc.h:
* gst/app/Makefile.am:
* gst/app/gstapp.c:
Remove AppSrc/AppSink that are moving to -base. Partially fixes
#564421