Remove bin.lua calls from some scripts and libraries

scripts/snmp-win32-software.nse

@@ -1,9 +1,9 @@
 local datetime = require "datetime"
-local bin = require "bin"
 local nmap = require "nmap"
 local shortport = require "shortport"
 local snmp = require "snmp"
 local stdnse = require "stdnse"
+local string = require "string"
 local table = require "table"
 
 description = [[
@@ -83,12 +83,12 @@ local function get_value_from_table( tbl, oid )
 end
 
 local date_xlate = {
-  year = 2,
-  month = 3,
-  day = 4,
-  hour = 5,
-  min = 6,
-  sec = 7
+  year = 1,
+  month = 2,
+  day = 3,
+  hour = 4,
+  min = 5,
+  sec = 6
 }
 
 -- translate date parts to positional indices for datetime.format_timestamp
@@ -119,7 +119,7 @@ local function process_answer( tbl )
     if ( v.oid:match(sw_name) ) then
       local objid = v.oid:gsub(sw_name, sw_date)
       local install_date = get_value_from_table( tbl, objid )
-      local install_date_tab = { bin.unpack( ">SCCCCC", install_date ) }
+      local install_date_tab = { string.unpack( ">I2 BBBBB", install_date ) }
       setmetatable(install_date_tab, date_metatab)
 
       local sw_item = {