[TYPO3] change default startup backend module

[Tapio Markula]

serge vleugels
> Hey Tapio,
> 
> I was looking for this functionality for a while as a client of mine is
> buggin me constantly about it.
> 
> I downloaded your extension. But there is no mention of it in the doc.
> Can hint me pls ?
Sorry I have missed to add these features to the manual.
Here an example
#must not be set if used default starting module
setup.override.startPage=
setup.override.defaultMainModule=web
setup.override.startingModule=web_layout
mod.SHARED.saveUID=1

the last one saves into cookie the last opened page.
I should update some day the manual.