Further Work On Plone AddOns For LibreOffice Extensions/Templates Site

I fixed some internationalization issues within the Plone addons I used to run the LibreOffice extensions and templates website. I added also a function that searches for the latest unstable release of a project. If there is such unstable release it will be shown to the user of the website. I added a new slot to project view for this. The updated code is available in the github repository of The Documenta Foundation yet. It will soon be released and incorporated in Plone instance of the LibreOffice extensions and templates website.