examples/parse_args.h: improve help message
examples/aubioonset.c: use built-in silence
examples/aubiopitch.c: use built-in silence
examples/utils.c: print error messages on stderr
src/synth/wavetable.c: use fvec_zeros, fmat_zeros
src/vecutils.*: update for history
src/vecutils.*: remove cvec functions for clarity
src/spectral/fft.h: improve doc
wscript: add doxygen
wscript: doxygen has no target for now
src/cvec.h: clean up cvec api
src/fvec.h: clean up fvec api
src/fvec.h: clean up old doc
src/fmat.h: clean up fmat api
src/fmat.c: new_fmat() takes height as first argument
src/musicutils.h: minimal doc about windows