removed filter eme_rsvp_multifield_filter and added filters eme_rsvp_email_body_html_filter and eme_rsvp_email_body_text_filter

git-svn-id: https://plugins.svn.wordpress.org/events-made-easy/trunk@1026738 b8457f37-d9ea-0310-8a92-e5e31aec5664