src/pitch/pitch.c: add yinfast
src/pitch/pitch.c: return NULL if pitch_mode is NULL
src/pitch/pitch.c: return NULL if creation failed
src/pitch/pitch.c: fix error string
src/pitch/pitch.c: fail on wrong method, warn on wrong unit, improve error messages
src/pitch/pitch.c: declare internal functions as static
src/pitch/pitch.h: add aubio_pitch_get_tolerance
src/pitch/: add const qualifiers, filter_do_outplace to avoid modifying input
src/pitch/pitch.c: fix name in error messages
src/pitch/pitch.c: disable buggy optimisation for now
src/pitch/pitch.c: variant for aubio_pitch_slideblock using memmove/memcpy
src/pitch/pitch.c: allow for silence == 0, improve error message
src/pitch/pitch.c: check parameters
src/pitch/pitch.c: add Hertz as valid unit string
src/: improve build with -Wdeclaration-after-statement
src/pitch/pitch.c: add aliases for freq (hertz, Hz, and f0)
src/pitch/pitch.c: aubio_pitch_set_unit returns AUBIO_FAIL on fail
src/pitch/pitch.{c,h}: add silence gate, default at -50dB
src/pitch/pitchyinfft.c: adapt filter and shortest period to samplerate
src/pitch/: add first draft for specacf