ThemeChooser: Update German translation + copyright cleanup

Patch Set 1:	* update German translation
		* correct meaning of an the error message
		* remove whitespace
		* use unicode

Patch Set 2:	* remove whitespace

Patch Set 3:	* rename strings after comments
		* update copyright

Patch Set 4:	* update more copyrights
		* set item_count to translatable="false"
		* rename some strings

Patch set 5:	* correct copyright
		* rename some strings

Patch Set 6:	* fix some formatting issues
		* use HTML unicode for better visibility in code

Change-Id: I5fa29794df8b2e41a1e59d2d15662a76aa4503d9