cleanup datatypes mix used in binary cache

cleanup datatypes mix used in binary cache

We had a wild mixture of (unsigned) int, long and long long here without
much sense, so this commit adds a few typedefs to get some sense in the
typesystem and ensures that a ID isn't sometimes computed as int, stored
as long and compared with a long long… as this could potentially bite us
later on as the size of the archive only increases over time.