Plugin "Manage embedded files" is included in standard distribution of Moodle 2.6
This plugin will add a button to the TinyMCE text editor in Moodle that allows to manage files embedded in the current text area.
It also will scan the text in the text area looking for references to the files and list the missing or unused embedded files.
To install copy folder managefiles/ to lib/editor/tinymce/plugins/, login as admin and run upgrade script.
Works very good together with repository Embedded files