Support for multiple compiled fragments when downloading sourceMaps

- Fix 'Multiple fragment 0 sourcemaps found. Too many permutations.'
  when all permutations are compiled (user.agent not specified) or
  we simultaneously are compiling and testing with more than one
  browser.
- Added Test and ant task to run it.

Change-Id: I78851f29f27f6466fa2a7460d966a00fe5b5a1bb