exif-update

[thomasFRU]

I have added a lot of new exif-tags specially for canon and panasonic.
The tags are now shown in a fixed order and not alphabetically,
which depends on $exif_info. This var I've moved to exif_tags.inc.php
because it is used twice in other files.
To make it easier to update the exif-info from pictures, I've added
a new topic in the admin-tools, called update_exif. It scans the picture-table
deletes the associated data in the exif-table and writes the new data to the
db.
Because I'm using german-lanuage in my gallery, I've added new translations
for various tags only in the german.php and add this file for reference.

All changes are made on basis of version 1.4.20, you can find them in the
attached zip.

Have fun
Thomas