Add WordPerfect filetypes to functions.php

[morganestes]

WordPerfect document filetypes aren't listed in wp_ext2type() or get_allowed_mime_types() in functions.php. This patch adds the wp and wpd extensions to those functions.

[nacin]

Looks like the patch also adds htm to ext2type(), which is already in get_allowed_mime_types().

[morganestes]

Correct, get_allowed_mime_types() already had both html and htm, but ext2type() only had html listed in the code array, so I added htm to the array.

'code'        => array( 'css', 'html', 'htm',  'php',  'js' )

[dd32]

r14066 /trunk/wp-includes/functions.php: Add WordPerfect filetypes to Mimetype list. Props morganestes. Fixes #12849