PHP 7.1 and PHP 7.2: add TEST_TARGET to all extensions
This enables "make test" in every extension and eases
the test of changes to PHP.
I did ignore PHP 7.0 intentionally since it only receives
security updates and will EOL at the end of the year. Therefore
no great amount of work is expected for 7.0.
Bump PORTREVISION in ports depending on archivers/libzip.
libzip was updated to 1.3.0 in r450774, and its SOVERSION went from .4 to .5
after the removal of zip_archive_set_tempdir(). All dependent ports continue to
build fine without that symbol.