RFC: app open only once instead of instances in the different activities

[Fania Bremmer]

Ok, here I am quite fuzzy about the current implementation: are we 
opening always new instances of apps and documents for every activity or 
is it always the same?

** Proposed Change **
Having a way to use general apps that are needed always, not activity 
specific.

** Reason For Change **
Usecase: I want to check my private mails any time I want, not related 
to my current activity. Currenlty I need to create a "general" activity 
with that sort of apps in it, like also a chat program... I need to 
switch to this activity to be able to chat, even if I am using that chat 
maybe for different projects, contacts, activities.

** Implementation Details **