Update de.h

Add translation for audionotifications
Merge pull request #667 from nachfuellbar/patch-1

Update de.h
Fixed audio group playback bug in uTox.
Attempt at making --portable work on windows.
Fixed bug in last commit.
Update de.h
Update German translation
uTox can now mute a group chat by right clicking it in and selecting mute.
Added colors to group chat name in the friends list.

Blue means muted.

Red means it's making sound (or someone in it is streaming audio).
Merge branch 'patch-1' of https://github.com/ovalseven8/uTox

#
# Please enter a commit message to explain why this merge is necessary,
# especially if it merges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.
Merge branch 'patch-2' of https://github.com/sfan5/uTox