Option to enable updating before app start using command line args

[Matthiee]

In the application entry point we should add logic to allow updating using startup arguments.

Default behaviour: no?

Arguments:

• /update (update program instantly before the rest of the app is loaded)
• /silent or /s or /quiet (disable updating UI)

What to do in case of error/exception?

[Matthiee]

Fixed in #22