Refactored tree view to use instance's constructor->tree_view_options->show_view when not provided in the child_options for a sub-level; also added a new mapping for sections/objectives/controls, related_and_able_objects, to replace the former 4-5 smushed together subtrees
Merge pull request #392 from reciprocity/feature/tree-nodes-choose-show-views

Tree nodes can choose their own show_view templates