Layer changed event now only fires when the layer is added to a map
Merge pull request #1337 from aodn/issue-1321

Layer changed event now only fires when the layer is added to a map
Remove different default longitude value for AODAAC as the normal defaults should work.
Merge pull request #1347 from aodn/Issue_#1344

Remove different default longitude value for AODAAC as the normal defaul...
Load a (currently mocked) hierarchical search response in to a tree (accessible through a root `TreeNode`).

Also, deleted unused class `RefinementList`.
Hiearchical facets are now off by default (even in dev mode), until such time as the back end is ready.
Only mocking geonetwork search requests (instead of all proxied requests).
Skeleton implementation of `HierarchicalTermSelectionPanel`.

Doesn't do much as yet!
"Summary" searching is no longer used.
Loading summary results in to hierarchical facet panel.