Externalize package query

[rsbeckerca]

We have a request from curl to provide a query to locate the supported version using a URL. A sample query to do this is:

select version_number from versions v
inner join packages p on p.package_key = v.package_key
inner join files f on f.version_key = v.version_key
where p.package_name =    'curl-ssl3.0'
  and f.file_type = 'TNS/X'
  and v.version_key = (select max(version_key) from versions v1
                     where v1.package_key = p.package_key);

The curl prefix and TNS/X or TNS/E can be supplied in the URL (or translated from ia64 and x86_64. Adding the -ssl3.0 should be added in code. We could also create a mapping table for file_type between the external and internal names.