Libdmapsharing seems to have diverged from some expected naming
conventions and this is affecting the use of libdmapsharing from Vala
code. Rename DPAPRecordInterface and TYPE_DPAP_RECORD to make Vala
happy. This work will continue as I attempt to make use of more of
libdmapsharing from Vala code.
Signed-off-by: W. Michael Petullo <mike@flyn.org>