3 year old bugs in wp-admin file uploading

[tychay]

They're relatively minor:

• in media.php, $overrides was supposed to be a passable parameter (so it can be sent upstream to file.php) but Andy forgot to put it in.

• in file.php, there are a number of $$ calls where call_user_func is more appropriate (after all, you can overrides with a object->method call, but that will break $$).

• there is another bug in file.php where if it errors out before extract the wrong error handler may be called (if overridden). I DID NOT PATCH THIS, but I made a note of it int he comments.

Two patch files are attached

WordPress.com reference:
​https://wpcom.automattic.com/changeset/22464
​https://wpcom.automattic.com/changeset/22365

Patch to file.php

patch to wp-admin/includes/media.php

Just a quick mention on the patch, You've got some WP.com specifics in there. (And that unfiltered_uploads check shouldnt need removing anymore, 2.8.5 removed unfiltered_uploads unless specifically enabled via a Define..)

Updated patch.

(In [13290]) Pass overrides. Allow ref array calling. Props tychay. fixes #12278