emotion_generic: fix permissions, resource leaks and error handling.

emotion_generic: fix permissions, resource leaks and error handling.

 - create permissions as 0700, this should be private to the running user.

 - do shm_unlink() on error, prevents resource leaks;

 - apply close() on error, prevents resource leaks;

 - handle strerror() properly.

 - shm name uses process id, object name and ecore's time, should be
   cleaner and avoid possible clashes

 - ecore_exe do not need to read from slave stdout/err, this removing
   the flags allows messages to come visible at terminal.