moved core class to core folder and sub namespace
added a class StackSet<T>  that can take a custom IEqualityComparer<T> to replace the Stack in StronglyConnectedComponentFinder.
added the class VertexBuilder that can build vertex graphs from a source list and a dependencySelector
VertexBuilder can handle null results from dependencySelector (treats them as no dependency)
- changed tabs to spaces
- added the class DependencyResolver that has extension methods to build sorted sorted dependency component lists using a lambda
-> also added VertexValueComparer, DependencyCycle
- ported all tests of StronglyConnectedComponentTests to use DependencyResolver
updated readme.md
-added doc comments to DependencyResolver, VertexBuilder and VertexValueComparer
- VertexBuilder.Buildvertices is no longer an extension method
- DependencyCycle.Dependencies is now a set of DependencyCycle
- References to vertices in cycles should now be much easier to work with
- moved some code of VertexBuilder into a non-static class
- found a last place in  StronglyConnectedComponentFinder that wasn't using the comparer
- moved FlattenCyclicDependencies to DependencyCycleMerger.MergeCyclicDependencies and made it more flexible
- added some tests and a test base class
- moved TestValue into its own file
- added a bit more description to the readme (and mention the Merge feature)