Fix for ExtractTask does not check output directory (ticket 3852)
Output to stderr, not stdout
Merge pull request #1301 from tersmitten/extracttask-output-directory-bugfix

Fix for ExtractTask does not check output directory

Fixes #3852
Only try to use CakeErrorController if AppController exists.

This fixes missing error pages when there are parse errors in
AppController.

Fixes #3850