[squashed] fix Issue 313

+PackageExp & ScopeDsymbol::packages
+ok?
+clean
Add test for issue 313
Remove PackageExp
One Package::resolve
+1 for link packages
+OK link packages
+consider static import
fix multiple package hierarchy merging
+1
+function local import + self module access by FQN
+clean & move
+x
fix test
+clean!
Fix access violation
Fix tests
fixup
+fix Scopedsymbol::search for not prefer FQN.