german translation

some words may not fit 100% but most of it is translated in formally
style.
Update ger/LC_MESSAGES/model_validation.po

changed language es_ES to de_DE
Update ger/LC_MESSAGES/default.po

changed language es_ES to de_DE
Update ger/LC_MESSAGES/default.po
Update ger/LC_MESSAGES/model_validation.po
Update ger/LC_MESSAGES/default.po
Update ger/LC_MESSAGES/default.po

small correction
Update ger/LC_MESSAGES/default.po

small correction
Merge pull request #1 from cerfribar/master

First Concept of German Translation