option for pack_install/2

Dear all,

Would it make sense to have an override/1 option in pack_install/2? 
When 'true' the system skips the question about overriding existing
installed version of pack.

Also, there is no documentation for option interactive/1. 

Regards,

Nicos Angelopoulos.

ps1
	in page: http://www.swi-prolog.org/dogfood.html
	 following reason -> following reasons
	visiters -> visitors
	contributers -> contributors 

ps2
	great to see pengines package included in distribution. congrats.