There are multiple parts to this item. We may want to break these into sub-tasks once work on this begins.
1. Whenever an item is selected in a project build path, we should index that item once, if it is not yet indexed
2. Removing the last reference to an item in a project build path (across all projects in the workspace) should cause that item's index to be removed
3. JSIndexQueryHelper should allow a list of indexes to be supplied with the idea that either all indexes will be queried, or by querying the indexes in order, querying stops with the first index containing the desired element.
4. Once this system is in place, we should include the current workspace-level metadata as a project build path item
5. Once this system is in place, we should update the presentation of the Index View to show all active indexes for the selected project
6. We will need to remove the current (hacky) implementation where we shim in the project build path items when indexing a project