added acs_mail_base64_encode - a tcl proc that uuencodes
fixed acs_mail_set_content to use CR
same for acs_mail_set_content_file
added acs_mail_uuencode_file to uuencode a file
changed acs_mail_encode_content a lot to properly read data from the CR and encode it as needed
changed recursive db_foreach to a db_list_of_lists followed by a foreach to prevent running out of handles
added a check of MIME type to decide whether to add 'Content-Transfer_Encoding: base 64'
commented out the code that puts To: and From: address into Headers to prevent duplicate To: and From: addresses in the email
changed acs_mail_content_new to be private. doesn't make sense to call it without a message_body