Fix path based dependencies. See #282 and #253.

Fix usage of the selections file (was completely ignored) and improve diagnostic output.

Avoid querying the package registries repeatedly for invalid packages.

Fix null pointer dereference in DependencyVersionResolver when no project is loaded.

Use URL and Path types of vibe.d if available for better interop.

Rename UpdateOptions->UpgradeOptions and move it to dub.dub.

Properly support path based version selections.

Make DependencyVersionResolver public for external use.

block on ddox child process ...

- fixes SIGINT (ctrl+c) for 'dub -b ddox'

Resolve sub packages of the root package directly instead of using the package manager. Fixes #287.

Handle packages with invalid package descriptions gracefully and improve diagnostic output.

Fix path based dependencies to be ignored for version selections.

Let Dependency.toString() also contain the optional/path properties. ...

versionString is changed into a public property to support the use cases where only the version range is expected.

Fix resolution of optional and path based dependencies.

Disable log output during "dub describe" to ensure only JSON gets written. See #221. ...

Note that JSON will only get written when no errors occur. Otherwise the output will be the usual error messages.

Fix getting the versions of each package during dependency graph resolution.

Reinitialize the project after upgrading dependencies.

Fix handling of overriding selections and let printUpgradesOnly fail gracefully.

Move DependencyResolver to its own module and reorder Version<->Dependency.

Rename Project.mainPackage to rootPackage. ...

Root package better describes the package's role of the root of the dependency hierarchy.

Implement a new dependency resolution algorithm with support for selections. ...

The new algorithm is completely rewritten to be able to find any valid combination of dependencies/versions. The old one could error out in cases where a valid dependency tree could have been built. Now the current selections are also taken into account when invoking without UpdateOptions.upgrade.

Some side changes:
 - Comparing branch versions is allowed now to enable sorting the full set of versions of a package
 - DependencyGraph and RequestedDependency have been removed

Rename fields in Project and load the root package only once.

correct imports

Integrate the "dub select" functionality in "dub upgrade".

Make some cosmetic changes to dub version selections. ...

- Adjust code style
 - Let "dub select" output a simple package->version map instead of package->{version, dependencies}
 - Rename dub.select.json to dub.selections.json.

Merge branch 'dustmite'

Preparing dub select command. dub select will select the currently used versions and write them to a file, so that dub can later use this information to rebuild this exact state. This will also be used to override dependencies with either branch versions or not matching versions (to resolve conflicts). (All of this if to be implemented). ...

Other changes:
- Added Version.UNKNOWN, which could be later used for undetermined package versions instead of ~master.
- Added Dependency to/fromJson.
- Added Dependency alias "*" for ">=0.0.0".

Not catching Throwable when metadata is fetched. ...

Documentation updated.

Cleaning up exception handling for dub remove and not catching Throwable somewhere else than commandline.d.

Improve wording.