fix(eChecklist-import): Fix error with formulas in status column

This should remedy the reported behavior of statuses quietly being changed to "Not Reviewed".
scan.inc - Added new set_Host_Error method to set the error value for a specific host
parse_excel_echecklist.php - explicitly check for the status to equal 1-of-7 expected values, if not, add note to finding, set scan error message, and default status to "Not Reviewed"
export.php - Added cell lock for A11:E{last row} with the default password of "sagacity" (all lowercase)

Fixes #80

ste/export.php

@@ -299,6 +299,7 @@ foreach ($findings as $worksheet_name => $data) {
       ->applyFromArray($borders);
   $sheet->freezePane("A11");
   $sheet->setAutoFilter("A10:{$sheet->getHighestDataColumn()}10");
+  $sheet->protectCellsByColumnAndRow(1, 11, 5, $sheet->getHighestDataRow(), "sagacity");
 
   updateHostHeader($sheet, $data['target_list'], $db);