increment(): check that the given value is reference counted
increment(): check that the given value is reference counted

remicollet/libsodium-php,paragonie/libsodium-php,thebigb/libsodium-php,paragonie/libsodium-php,jedisct1/libsodium-php,paragonie/libsodium-php,remicollet/libsodium-php,jedisct1/libsodium-php,remicollet/libsodium-php,thebigb/libsodium-php,jedisct1/libsodium-php