OO-798, OO-797, OO-796: update the webdav implementation based on Tomcat, make OpenOLAt work under root context, small refactoring of the dispatchers, push raw files dispatcher to its own servlet, implements Digest authentication...

OO-690: add header to the word document with page number, add export to docx in question pool, polish some styles...

OO-750: refactor the mail package to provide a MailManager as a service, enable sending HTML E-Mails, add a customizable E-Mail template with a small editor in admin

OO-622,CL-225: remove username from GUI in place where is not really needed and students can see it. Mark others place with //TODO username where it need more works and/or the username is only visible by author/coach/admin... Additional fix the setup sql for MySQL (index too long).

no-jira: fix documentation of REST API, fix wrong path of the LogWebService, backport RegistrationWebService to OpenOLAT with its unit tests

OO-291: first step: move business gourp manager to a business group service, remove dependency to the context...