Run distro-sync at the beginning of the update.

The spare_deps method had to double-guess what packages might still be
needed.  And it was awfully slow in many circumstances.  This is solved
by just upgrading everything early and then doing the final tweaks in a
separate transaction.
Obey runspma from distrosync.

It was running yum distrosync inconditionally, which is obviously not
what we want.

Tests are adjusted, and so is their documentation.
Adapt distrosync to the refactored yum execution.
Fix typo in a comment.
Initiate a method for sparing dependencies.

It should be faster than the previous attempts.
Fix test documentation.
Check for dependencies of packages to be installed
Purge removal candidates with reverse dependencies
Make whitespaces consistent
Print the names of the installed packages too

Allows to remove quickly any already installed package that has not been
completely specified from the list of packages to install.

This should make Yum invocations much shorter, often without any
"install" line at all.  It should also make the "spare_dependencies"
method much faster, since it will do much smaller queries.
Add a simulation of how to reduce transactions
Spare dependencies with --requires in most cases

The --whatreq path is much slower, but it still is a good speedup for
installations, where an operator may be actually waiting for the node.
Remove unused variable.
Add a basic smoke test
Use the same build tools as the rest of Quattor.

Includes some changes so that it doesn't download the entire world
without my knowledge.
Replace the mentions to SF with GitHub.
End the ccm.cfg file with a newline.
Add smoke tests to ncm-libvirtd.
Use the latest build tools.
Simplify the POM file.