added first version of wavetable
Merge branch 'develop' of aubio.org:/git/aubio/aubio into wavetable
src/synth/wavetable.c: fix frequency interpolation, add amp to do_multi
src/utils/parameter.{c,h}: added simple parameter with linear interpolation
src/synth/wavetable.c: use parameters for frequency and amplitude
src/aubio.h: add utils/parameter.h
examples/: use wavetable to play pitch and to replace woodblock