Add support for big files (lager than 2GB)

The following allows installing RPM packages with size higher
than singed integer max value on 32-bit and 64-bit systems.

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Merge pull request #1 from davidlt/add-support-big-files

Add support for big files (lager than 2GB)