Revert "seq, portid: change type to uint32_t"

This reverts commit c015a39655877d35fa917c74852637a71a949f57.

We cannot change the API, it may break compilation of existing
applications.
Revert "parse: change offset type"

We cannot change this, it breaks the ABI.

This reverts commit 3223cba908efaba6738ec59222278ff248fa9cdf.