flac.md : Some more fixes: errors, language. #43

Job	Run time
build (integer-only-library, -DFLAC__INTEGER_ONLY_LIBRARY)	3m 3s
build (no-ogg, --disable-ogg)	3m 20s
build (32-bit-words, --disable-64-bit-words)	3m 19s
build (no-asm, --disable-asm-optimizations)	4m 18s
	14m 0s

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