[package] pppd:

[package] pppd:
	- localize variables in setup script
	- implement demand option as true boolean so that 0 actually disables it
	- don't overwrite user supplied dns servers if demand is enabled
	- toggle peerdns default value, use 1 if no user supplied dns server is set, 0 otherwise
	- reset resolv.conf.auto before setting up dns

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@21280 3c298f89-4303-0410-b956-a3cf2f4a3e73