de-translation: Insert Menu (start)
de-translation: Lilypond menu

With mnemonics
And check all translations of 'engrave'
de-translation: Tools Menu

With Mnemonics (and submenus)
de-translation: Window Menu

With Mnemonics
de-translation: Add missing translations (WIP)
Merge pull request #136 from uliska/de-translation

De-translation: More menus
Thanks!