Problems with specs2 test filters and test xml

https://github.com/bazelbuild/intellij/pull/155#issuecomment-342945215

> If I create a failing test at `Foo#bar::baz`, `Foo#bar::` and `Foo#` succeeds because they're running an empty suite.

https://github.com/bazelbuild/intellij/pull/155#issuecomment-343571800

> The specs2 test.xml seems to generate incorrect test suites right now:
>
> `com.example.TestClass#foo should::do bar`
> Produces:
> * test suite `TestClass` (should be fully qualified `com.example.TestClass`)
> * test suite `foo should` (should be fully qualified `com.example.TestClass#foo should` or something else instead of `#`)
> * test case `foo should::do bar` with class name `com.example.TestClass` (this one seems correct)

https://github.com/bazelbuild/intellij/pull/155#issuecomment-344440875

> If you have multiple test scopes with tests of the same name, e.g.,
> ```
> TestClass
> "foo" should "do blah"
> "bar" should "do blah"
> "baz" should "do blah"
> ```
> running any of them (e.g., "--filter=TestClass#foo::do blah", "--filter=TestClass#bar::do blah", "--filter=TestClass#baz::do blah"), will only run the first one (i.e., "foo" should "do blah").

Start by reviewing the referenced comments in bazel-contrib/rules_scala#339 and the linked pull request. Reproduce the reported specs2 filters and test XML output for nested test names and duplicate scopes; done means filters select only the requested test and generated suites use the correct names and qualification.

Written by the indexing model from the issue text.