Merge pull request #365 from thknepper/master

german translation for admin tab
Add user setting descriptions so they can be more verbose/translated
Add possible user settings constants
Use User constant instead of hard coding
Use User constants instead of hard coding
Use better descriptions for user settings
Fix web commits with rework of admin descriptions
Fix folder with no songs showing header on legacy album view
Automatically filter out null preferences

This should make it so people on older versions of servers won't even see settings which won't do anything for them.
Doing a exists check first is faster then deserializing
Pull back a little on multi-disc replacement since some have bad album data
#171 update german translation