Let --nodeps work for any command of the build/generate category.

Remove log message previously used for debugging.

Fix running "dub test" on an explicitly named package.

Implement the "test" command.

Tweak help screen formatting and add a few short options.

Group commands by category in the help screen + add a skeleton for the "test" command.

Fix parameter handling of the "init" command.

Add --force switch for "dub run" and "dub build" and fix --rdmd.

Let --annotate work for all commands.

Defer initialization code so that displaying help works immediately and without the danger to fail.

Revamp the command line interface with cleanly separated command implementations.

Fix naming convention of PlacementLocation.

Only install pre-release versions with "dub upgrade --prerelease" if release versions are also available.

Don't warn about missing package.json in CWD when a different package was selected by name.

Move command line processing to a separate module.