Finished code cleanup of the sieve library itself.

src/lib-sieve/mcht-contains.c

src/lib-sieve/mcht-is.c

src/lib-sieve/mcht-matches.c

src/lib-sieve/sieve-result.c

src/lib-sieve/sieve-result.h

src/lib-sieve/sieve-script-private.h

src/lib-sieve/sieve-script.c

src/lib-sieve/sieve-script.h

src/lib-sieve/sieve-types.h

src/lib-sieve/sieve-validator.c

src/lib-sieve/sieve-validator.h