* Use Avails for export resolution

* Support reexported modules

* Factor out availExportItem

* Use avails for fullModuleExports

* Don't use subMap in attachInstances

* lookupDocs without subMap

* Completely remove subMap

* Only calculate unqualified modules when explicit export list is given

* Refactor

* Refine comment

* return

* Fix

* Refactoring

* Split avail if declaration is not exported itself

* Move avail splitting