some fixes for blackboard, added questype replacements in xml template, now the questiontype is inserted within exams2blackboard() and bb_questiontype(). Added formating the XML files, only temporary, I think we don't need formatting...

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/exams@717 edb9625f-4e0d-4859-8d74-9fd3b1da38cb