Stupid simple code to mark a node as changed
Extracted the node initialization in ASTNodeTest
Marking the change of a single property in the node
Import reorg and removed some warnings

Just being pedantic really
Added owner information
Extracted the default owner to a constant
The default owner is "base"
Added the expression property of a node

Needed it in a test
The update now has an Owner
Marked the old constructor as deprecated
Operations now have a owner
History now has an owner