zscanner: upgrade the API and add a state parsing support

scripts/update-parser.sh

src/zscanner/error.c

src/zscanner/error.h

src/zscanner/scanner.c.g2

src/zscanner/scanner.c.t0

src/zscanner/scanner.h

src/zscanner/scanner.rl

src/zscanner/scanner_body.rl

src/zscanner/tests/TESTS

src/zscanner/tests/data/00-3_general.in

src/zscanner/tests/data/00-3_general.out

src/zscanner/tests/data/00-4_general.in

src/zscanner/tests/data/00-4_general.out

src/zscanner/tests/data/06-3_INCLUDE.out

src/zscanner/tests/processing.c

src/zscanner/tests/unittests.in

src/zscanner/tests/zscanner-tool.c