added new generic installer and uninstaller bash scripts.

DnsServerApp.NETCore/uninstall.sh

@@ -0,0 +1,40 @@
+#!/bin/sh
+
+dotnetDir="/opt/dotnet"
+dnsDir="/etc/dns"
+
+echo ""
+echo "================================="
+echo "Technitium DNS Server Uninstaller"
+echo "================================="
+echo ""
+echo "Uninstalling Technitium DNS Server..."
+
+if [ -d $dnsDir ]
+then
+	if [ "$(ps --no-headers -o comm 1 | tr -d '\n')" = "systemd" ] 
+	then
+		sudo systemctl disable dns.service >/dev/null 2>&1
+		sudo systemctl stop dns.service >/dev/null 2>&1
+		rm /etc/systemd/system/dns.service >/dev/null 2>&1
+		
+		rm /etc/resolv.conf >/dev/null 2>&1
+		echo "nameserver 8.8.8.8" >> /etc/resolv.conf
+		echo "nameserver 1.1.1.1" >> /etc/resolv.conf
+	else
+		rm /etc/supervisor/conf.d/dns.conf >/dev/null 2>&1
+		service supervisor restart >/dev/null 2>&1
+	fi
+
+	rm -rf $dnsDir >/dev/null 2>&1
+
+	if [ -d $dotnetDir ]
+	then
+		echo "Uninstalling .NET Core Runtime..."
+		rm /usr/bin/dotnet >/dev/null 2>&1
+		rm -rf $dotnetDir >/dev/null 2>&1
+	fi
+fi
+
+echo ""
+echo "Thank you for using Technitium DNS Server!"