--unpack-tarball doesn't download any contents now (Closes: #551838)

Make --unpack-tarball works properly (it means, just extract tarball and configure it without any downloads)

• --unpack-tarball just exec "first_stage" and "second_stage" phase, ignore "finddebs" and "dldebs"
• Split "save_variables" phase from "first_stage"
• Some options overwrites phases info each other, so make them exclusive
• Save some package info to file to include to tarball made with --make-tarball