recursiveModuleCompileToSingleFile: chdir on reject

Make `process.chdir` to original dir if compilation if failed. For success result chdir revert already exists.

It need it you need to execute other scripts after traceur compilation. And if it is failed - dir should be changed to original.
I'd rather have the `chdir()` call inlined or use the `revertCwd()` in both places, but not mix/match.