Start of new ring_buffer transport.

Start of new ring_buffer transport.
2009-03-04  David Smith  <dsmith@redhat.com>

        * runtime.h: Added _stp_exit() prototype.
        * transport/ring_buffer.c: New file.
        * transport/transport.c: Removed unneeded utt_trace lines.
        Includes transport/ring_buffer.c.
        (_stp_transport_fs_init): Calls _stp_transport_data_fs_init().
        (_stp_transport_fs_close): Calls _stp_transport_data_fs_close().
        * transport/transport.h: Added prototypes.