Fix skipped target pointing to a skipped target

Add .dll.config for tests

Need to specify binding redirects for xUnit when loading MSBuild

Represent skipped targets separately in the tree

Fixes #504

Bugfixes

v2.1.500

Don't normalize path before entering GetSourceFileText.

Better support for $additem

v2.1.497

Display the evaluation items as AddItem

Fix bugs

v2.1.494

Add some structure under the Mmp task.

Better support for TargetSkippedEventArgs

v2.1.488

Drop Building with tools version Current messages.

Support file format version 14

Better target skipped support

Fix statistics WPF issue

v2.1.480

Add a TODO comment.

Fix search for derived tasks

v2.1.476

Fix searching for derived tasks

Binlog loading perf improvements

Bugfixes and better support for file format version 13
Faster binlog loading