Validate + sort relocations in rpmte at create time

Validate + sort relocations in rpmte at create time
- instead of storing "raw" relocations in rpmte to be passed down to
  rpmRelocateFileList() for copying over and sorting etc, do the work
  just once at rpmteNew() time
- much of the real work to relocate header contents still needs to be done
  twice as the header gets thrown and needs to be reconstructed in
  rpmtsProcess()