Expanded retrieve requests for repack

The retrieve requests now carry all the information necessary to create the archive jobs.
Retrive requests carry an isRepack boolean. The distinction between repack and non-repack behaviour
is pushed as low as possible in the api (in the object store) so that client code can be more
generic. For the same reason, the
The expand repack mode (re-creation of missing tape files) is not supported yet.
Changed the represenation of copy numbers to uint32 (as this is the smalled number supported but protocol buffers).
Added ArchiveRoute::StorageClassMap and ArchiveRoute::FullMap to store archive routing in memory.
Added repack buffer base URL support, and mechanism to compute temporary copy location in disk cache.
Fixed bug in ObjectOps<>::asyncInsert();
Inplemented the path generation for repack disk storage (<BaseURL>/<VID>/<FSeq (09%d)>).