plugins import, tickets import, bugzilla import: comments handling: - comments are put in "comments" key in import data, it's a list of microblog data - in resulting item, the comments uri is put in comments_uri field - (plugin import) root_service and root_node are kept in session - (plugin ticket) reporter name is now in "reporter" key instead of "reporter_name" - (plugin bugizlla): if not reporter name is found, first part of email address is used