Add ability to choose upstream DNS servers

Give the user the ability to choose between Google and DynDNS upstream
servers.  Then insert the chosen DNS servers in to
/etc/dnsmasq.d/01-pihole.conf.  Todo: extend choices to include manually
entered DNS servers.

automated install/basic-install.sh

@@ -253,6 +253,27 @@ else
 fi
 }
 
++setDNS()
+ +{
+ +DNSChoseCmd=(whiptail --separate-output --radiolist "Select DNS Servers" $r $c 2)
+ +DNSChooseOptions=(Google "Use Google's DNS Servers" on
+ +		  DynDNS "Use DynDNS's DNS Servers" off)
+ +DNSchoices=$("${DNSChoseCmd[@]}" "${DNSChooseOptions[@]}" 2>&1 >/dev/tty)
+ +
+ +case $DNSchoices in
+ +	Google)
+ +		echo "Google selected."
+ +		piholeDNS1="8.8.8.8"
+ +		piholeDNS2="8.8.4.4"
+ +		;;
+ +	DynDNS)
+ +		echo "DynDNS selected."
+ +		piholeDNS1="208.67.222.222"
+ +		piholeDNS2="208.67.220.220"
+ +		;;
+ +esac
+ +}
+
 installScripts(){
 $SUDO echo " "
 $SUDO echo "::: Installing scripts..."
@@ -279,6 +300,8 @@ if grep -q $dnsSearch $dnsFile; then
 fi
 $SUDO curl -o /etc/dnsmasq.d/01-pihole.conf https://raw.githubusercontent.com/jacobsalmela/pi-hole/master/advanced/01-pihole.conf
 $SUDO sed -i "s/@INT@/$piholeInterface/" /etc/dnsmasq.d/01-pihole.conf
+$SUDO sed -i "s/@DNS1@/$piholeDNS1/" /etc/dnsmasq.d/01-pihole.conf
++$SUDO sed -i "s/@DNS2@/$piholeDNS2/" /etc/dnsmasq.d/01-pihole.conf
 }
 
 installConfigs(){
@@ -422,6 +445,8 @@ chooseInterface
 # Let the user decide if they want to block ads over IPv4 and/or IPv6
 use4andor6
 
+# Decide what upstream DNS Servers to use
+setDNS
 
 # Install and log everything to a file
 installPihole | tee $tmpLog