Fix 0010817: View status column shows integer instead of icon

When setting the view_status column within account_manage_columns_page,
the view issues list only shows the integer value of the view_status
field.

This correction will ensure that the protected/padlock icon is shown for
private issues. For public issues, no icon is shown.

The protected/padlock icon has been removed from the end of the summary
column as it is duplicated by this now working view_status column.

The view_status column is also now sortable, which makes it a little bit
easier to find all the private issues at once.