• Improve wording, accuracy, and readability of most options' descriptions
• Drop few descriptions that have suitable default versions in standard pool
• Remove initial LIB_DEPENDS: libsamplerate is pulled up via DSP option, and remaining libmad was converted to its own option
• Since most options have their corresponding --disable/enable switches (FOO -> --{dis|en}able-foo), rename some options that violated this rule (ADP -> ADPLUG, EQ -> SUPEREQ, WAV -> WAVPACK, and WILD -> WILDMIDI) for consistency (in case of WAVPACK, it was actually an error to masquerade it as WAV)
• Wrap overly long lines and sort USES values while here
• Stop advertising that the build on PowerPC is broken (it builds fine on my Mac mini G4)

Approved by: vg (maintainer)