1.0.0

This is a major change!

Now system execution order in each group is specified in a node-based editor instead of a simple list. This lets you visually explore each system's dependencies. The graph is more robust than the list-based approach since the list hid the true dependencies of each system. The visible graph is also easier to use than Unity's default UpdateBefore and UpdateAfter attributes which require re-compilation after editing and are distributed across multiple source files.

This also updates the Entities dependency from 0.50.1 to 1.0.0.