Only show JUnit temp window if errors; close existing on success

Mimics behavior of tpope's fireplace.vim, and lends to a
smoother, more satisfying experience :)
Add some missing code, fix some bugs

Forgot to copy over the regex line from when I was editing
in .vim/eclim---whoops!
Fix regex and other issues (hurray working from memory...)
Merge remote-tracking branch 'dhleong/dhleong/OnlyShowJUnitWindowOnFailure'
minor updates to latest :JUnit behavior patch

- remove setting of unnecessary global variables
- use eclim's Echo function when diplaying the status on a successful
  junit run.

refs #351