fix 2.064 merge issue

- The function printThrowable relied on the Throwable.toString(sink)
  overload from #636 which is not available in 2.064.

- Fixed by re-adding the old exception print code.
Merge pull request #651 from dawgfoto/fixMerge2.064

fix 2.064 merge issue
add missing files to MANIFEST
Merge remote-tracking branch 'upstream/2.064' into ldc-merge-2.064