Refs #17451 Forum; added the possibility to override tinymce styles by uploading a DTML method called custom_css. This gets concatenated to the additional_styles resource which is loaded by TinyMCE from portal_editor

git-svn-id: https://svn.eionet.europa.eu/repositories/Naaya/trunk/eggs@20653 a0171fae-0946-0410-966d-b1775066cd26