Update UITableView+LongPressReorder.m

Added ability for user to enable use of Custom Cell by useCustomCell property.
Example [self.tableView setUseCustomCell:YES]; // Default is NO
Update UITableView+LongPressReorder.h

Added ability for user to enable use of Custom Cell by useCustomCell property.
Example [self.tableView setUseCustomCell:YES]; // Default is NO
Fix warnings