Revert "Removed tests"

This reverts commit c06bbbef0e0a5a4637d51e22f991260537b69da1.
Setup getDeclarationFor to go to class name of referenced class if no default constructor exists.
Added tests, new mock for arbitrary dart file in empty directory and removed one-test
Pin down polymer and fix possible widget library bugs
new line nit
Merge pull request #2162 from financeCoding/bug_fix_widgets

Pin down polymer and fix possible widget library bugs
Update markdown.dart

fix a spelling mistake
Merge pull request #2160 from dart-lang/umop-linking-add_instantiations

Link to class name of referenced class if no default constructor exists.
Merge branch 'master' into add_status
comments.