Spelling fixes for Lua files

Mostly in documentation/comments, but a couple code bugs were caught,
including a call to stdnse.pirnt_debug and a mis-declared variable.

scripts/couchdb-databases.nse

@@ -46,7 +46,7 @@ local DISCARD = {}
 --- Removes uninteresting data from the table
 -- uses the DISCARD table above to see what
 -- keys should be omitted from the results
--- @param data a table containg data
+-- @param data a table containing data
 --@return another table containing data, with some keys removed
 local function queryResultToTable(data)
   local result = {}