Fix make distcheck.

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/Makefile.am

 bin_PROGRAMS = audiowmark
 
-audiowmark_SOURCES = audiowmark.cc wavdata.cc fft.cc
+audiowmark_SOURCES = audiowmark.cc wavdata.cc wavdata.hh fft.cc fft.hh
 audiowmark_LDFLAGS = $(SNDFILE_LIBS) $(FFTW_LIBS)

src/TODO

 - non-blind decoder
 - standard tests (-> mp3, ->ogg, ...)
-- refactor fft
 - peaq scores