Merge pull request #268 from fdeberle/announcements

Fix for issue #267
Propose URL from Title on edit activity page
create message id from sha1 hash of file content if it was not available
new Mail constructor throws an error if its argument has no valid id property
Merge branch 'master' of git://github.com/softwerkskammer/NeuePlattform-Implementierung
refactor : rename js file and method
add scroll bar to mail index
Merge pull request #271 from dpolivaev/master

Improvements for mailarchive and activity editor
do not submit the form on the Vorschlag button click
Persistency store fails to save object without id or with id === null
Merge pull request #273 from dpolivaev/master

 	Don't submit the form on the Vorschlag button click
#270: Add author automatically