AppCache Info box

Added a AppCache Info box. That will be shown when a new version is
available.
If clicked on, it will reload the page, to display the new version.
For mobile zoom

I hope that this will fix the zoom-level on smartphones.
Month will be a column.
Internal memory in isOstern (Easter)

The isOstern (isEaster) function will now have a internal memory, that
will store the easter sunday of a given year.
Version update
Merge pull request #2 from Terreii/master

Update info & Cach in isOstern