PropertyEditor Locations, Bugfixes
#CHANGE: Each PropertyEditor now knows its location and operates on "absolute" coordinates (relative directly to the PropertyGrid control).
#CHANGE: All PropertyEditors now use a shared splitter distance, regardless of individual indent values.
#FIX: Fixed several rare crash bugs when multiselecting over collections with a different reflected type than declared type.
#REMOVE: PropertyEditors are no longer IDisposable, since there was no need for them to be.
#REMOVE: Removed PropertyEditor value converter support, since it was no longer used.