Add an option to test:all task to show full output

The variable `full_output` in lime_harness class will allow `test:all` task to output full path of the current test.

Before:

    [sfMyAwesomePlugin] functional/sfMyAwesomePluginServiceTest..............ok

After:

    [sfMyAwesomePlugin] /var/www/htdocs/test/sfMyAwesomePlugin/functional/sfMyAwesomePluginServiceTest.php..ok

This is more "strict" and less straight but more efficient to copy/paste the test and relaunch it.