MDL-15777 - updated most of the portfolio code to use files api.

Not done:

- forum (the rest of the module isn't using files api yet)
- database mod (touches other parts of the code (ods and excel libs)
- portfolio download plugin (needs discussion with petr about userfiles)

all of these have been disabled in the meantime.

mod/data/lib.php

@@ -2472,7 +2472,7 @@ class data_portfolio_caller extends portfolio_module_caller_base {
         return sha1($str . ',' . $this->exporttype);
     }
 
-    public function prepare_package($tempdir) {
+    public function prepare_package() {
         global $DB;
         $count = count($this->exportdata);
         switch ($this->exporttype) {