Silence compiler warnings in -Wformat mode.

Passing SQLINTEGER/SQLUINTEGER sprintf "%d", "%ld" modifiers gave a warning
on some systems (at least on my 32-bit Debian system) .
Silence more compiler warnings in -Wformat mode, in regression test.
Fix test case for big-endian systems.
Another round of -Wformat fixes.
Avoid the failure of odbcini-gen.