Rework symbol repair utility

  - set the currentOwner of the traverser before starting, otherwise
    it default to `RootSymbol`
  - replace `hasTransOwner` logic with a direct test for symbols
    that were originally owned by the call-site owner.

```
 ~/code/scalatest sbt
[info] Loading global plugins from /Users/jason/.sbt/0.13/plugins
[info] Loading project definition from /Users/jason/code/scalatest/project/project
[info] Loading project definition from /Users/jason/code/scalatest/project
[info] Set current project to scalatest (in build file:/Users/jason/code/scalatest/)
> macroprob/test
[info] Compiling 1 Scala source to /Users/jason/code/scalatest/target/scala-2.10/classes...
[warn] there were 10 deprecation warning(s); re-run with -deprecation for details
[warn] one warning found
[info] Compiling 1 Scala source to /Users/jason/code/scalatest/macroprob/target/scala-2.10/test-classes...
[info] MacroProblemSpec:
[info] - this should blow up during compilation
[info] Run completed in 310 milliseconds.
[info] Total number of tests run: 1
[info] Suites: completed 1, aborted 0
[info] Tests: succeeded 1, failed 0, canceled 0, ignored 0, pending 0
[info] All tests passed.
[success] Total time: 9 s, completed Apr 2, 2014 6:15:18 PM
>
```