'Date Deleted' removed from 'Configure Column' List

Users using the 'List View' could select/deselect the columns to be displayed from the 'Configure Columns'. 'Date Deleted' was one such column. But, outside of a trash folder it serves no purpose. Hence, as suggested in #750 (closed), the 'Date Deleted' column has been removed from the 'Configure Columns' pref.

This solves #750 (closed).

This is my first contribution towards XFCE. I am looking forward to taking part in GSoC this year.

Your feedback, would really help me. Thank you.