gui: add german translation

also correct typo in all language files
also remove dummy language files for ES and FI

german translation was done on omni crowdin by multiple translators:
https://crowdin.com/project/OmniROM/de#



result was updated in line with latest changes (as of 02032016) to en.xml


Change-Id: Iddd8dbee7e050833a4dc61174288514d408267f7
Signed-off-by: z31s1g <z31s1g@googlemail.com>