Implemented evaluation for the body test introduced by the body extension.

AUTHORS

src/lib-sieve/plugins/body/Makefile.am

src/lib-sieve/plugins/body/body.sieve

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

src/lib-sieve/plugins/body/ext-body-common.h

src/lib-sieve/plugins/body/ext-body.c

src/lib-sieve/plugins/body/tst-body.c

src/lib-sieve/plugins/imapflags/tst-hasflag.c

src/lib-sieve/sieve-address-parts.c

src/lib-sieve/sieve-match-types.c

src/lib-sieve/sieve-match-types.h

src/lib-sieve/tst-header.c