Deprecate wavread and wavwrite. * NEWS: Announce deprecation and replacement functions. * scripts/deprecated/wavread.m, scripts/deprecated/wavwrite.m: Moved from scripts/audio. Add deprecation message to docstring. Add deprecation warning to m-file. * scripts/audio/module.mk: Remove from build system. * scripts/deprecated/module.mk: Add deprecated versions to build system. * audio.txi: Remove functions from manual.