Further split the cli-tools to rpminstall, rpmquery and rpmverify

Further split the cli-tools to rpminstall, rpmquery and rpmverify
- Installing/erasing packages, querying and verifying require different
  amount of privileges on the system. Having separate binaries for
  these functionalities permits limiting the capabilities through
  SELinux and other similar security mechanisms: for example quering
  needs much less privileges than installing.
- For now, leaving /bin/rpm to be the Swiss Army knife it
  always was: capable of install/erase, query and verify. Eventually
  it should be turned into just a dumb wrapper which just execs
  the per-functionality binaries, but leaving that for later stage,
  as popt exec/aliasing doesn't quite seem to up to par with the task.
  Having the separate binaries available at least makes it possible
  for callers to specify the amount of privileges they need.