apt-solver3

Builds of the solver3 branch of apt

This is a new solver, enabled with --solver 3.0 option.

Key choices:
* We do not uninstall manually installed packages.
* We solve smaller choices before larger choices, i.e. A before A|B before A|B|C

It also adds new features:

* New --no-strict-pinning option for that solver (automatically enables it)
* autoremove is more aggressive, only keeping automatically installed packages in the strongest set

Known issues:
* The list of autoremovals cannot be shown if autoremove is not being done.
* Manually inst
* Error reporting is not quite there yet, set Debug::APT::Solver=3 and grep stderr for "Branch failed" to get more errors.