Fixed typos.
Inside of the PackageManager, change type of m_packages from Package[][string] to Package[], as there is no need for an associative array, currently.
Automatic discovery of sub-packages added to package manager.
With discoverable subpackages, the examples are named like their folder.
When it is allowed to name these differently, the package id would be rather strange for the normal usecase (e.g. a dependency on dub/examples/app/app would be required)
When a package having externally defined subpackages is installed, they work. Currently not tested with the registry.
Revert "With discoverable subpackages, the examples are named like their folder."

This reverts commit 440089bc8e0da76a24710b9ce4dc80378b62c883.

Automatic discovery is disabled.
Reverting unwanted commit.
Subpackages, which are defined external to the main package.json can be fetched from the registry. Eventually, the dependencies of all referenced packages will be fulfilled, but this is done by a hack where the metadata of the external package is inferred as having no additional dependencies. When the package is then fetched the state is re-evaluated and possible new dependencies will be resolved.
Make "dub.json" the primary choice for a package description and handle "package.json" as a fallback.
Keeping track of the saved json file in the journal and some smaller changes.
Properly saving the journal's filename of the package description.
Fix version(Linux) -> version(linux) - gotta love inconsistent naming...
Fix the configuration resolution algorithm.

The initial graph of the old algorithm contained edges to configurations that
couldn't themselves resolve all dependencies. These are now skipped, so that
only valid sub graphs exist. This avoids bogus "Could not resolve configuration
for package X" errors.
Only treat "main.d" and "<packname>/main.d" as "mainSourceFile" for library targets.
Reimplement the VisualD generator based on the new target generation code and fix link dependencies for static libraries.
Deprecate the "visuald-combined" generator.
Fix folder/filter structure for generated VisualD projects with multiple nested source libraries.
Only copy DDOX resources if newer on Posix.
Update change log.
Fix Project.getDefaultConfiguration to take the whole dependency tree into account.