Stop it being a singleton. This means it needs to be passed around a
lot. This sucks, but it's how it should be. I shouldn't be using a
global variable to get around this.
This is needed as Settings will soon become repo specific when we
support multiple repos.
This breaks saving the settings in a file, that feature was toggled off
anyway. It needs to be thought over again.
In the FlattenedNotesFolder we can have a filter to only show certain
notes. This is used for showing notes that match some tags. When the
note is added to this virtual folder it matches the tag, but later it
does not.
This contains the default editor / view / sortingMode / etc. For now the
folder settings are shared among all Folders. But the idea is that we
should be able to set different settings per folder (real or virtual)
