Implemented match type execution and activated match types :is and :contains.

...gins/comparator-i-ascii-numeric/ext-cmp-i-ascii-numeric.c

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

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

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

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

src/lib-sieve/sieve-common.h

src/lib-sieve/sieve-comparators.c

src/lib-sieve/sieve-comparators.h

src/lib-sieve/sieve-interpreter.c

src/lib-sieve/sieve-interpreter.h

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

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

src/lib-sieve/tst-address.c

src/lib-sieve/tst-header.c