This update removes the 16/24-bit sample type enum, now always being 24-bit
(other than a very small size saving, there's no practical benefit to storing
16-bit samples). This also reverses the field storage, so no on-load fixup is
needed, and stores the IR delays with 2 bits of sub-sample precision, allowing
for slightly better timing (after resampling, blending, etc).
AL_LOKI_quadriphonic is left alone since that is what the extension is called
and what code expects. All other instances have been fixed for consistency.