Merged changes from Pigeonhole v0.3.

src/lib-sieve/cmd-redirect.c

src/lib-sieve/edit-mail.c

src/lib-sieve/plugins/editheader/ext-editheader-common.c

src/lib-sieve/sieve-ast.c

src/lib-sieve/sieve-binary.c

src/lib-sieve/sieve-error.c

src/lib-sieve/sieve-validator.c

src/managesieve-login/client-authenticate.c

src/plugins/lda-sieve/lda-sieve-plugin.c

tests/extensions/editheader/alternating.svtest