Clean up string concatenations

Building a string with var = var .. "something" has miserable time
complexities. This commit cleans up a lot of that in scripts, focusing
on packing of data with bin.pack and concatenations within loops.
Additionally, a few instances were replaced with string.rep

scripts/http-git.nse

@@ -271,11 +271,7 @@ function action(host, port)
 
     -- Show what patterns matched what files
     for name, matches in pairs(info["interesting-matches"] or {}) do
-      local temp = name .. " matched patterns"
-      for _, matched in ipairs(matches) do
-        temp = temp .. " '" .. matched .. "'"
-      end
-      table.insert(new, temp)
+      table.insert(new, ("%s matched patterns '%s'"):format(name, table.concat(matches, "' '")))
     end
 
     if info["repository-description"] then