Improved install script for packaged telegraf:

* Start/stop service on Debian/Ubuntu
* Disable init-script/Systemd-unit on package removal

closes #747

scripts/post-remove.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+
+function disable_systemd {
+    systemctl disable telegraf
+    rm -f /lib/systemd/system/telegraf.service
+}
+
+function disable_update_rcd {
+    update-rc.d -f telegraf remove
+    rm -f /etc/init.d/telegraf
+}
+
+function disable_chkconfig {
+    chkconfig --del telegraf
+    rm -f /etc/init.d/telegraf
+}
+
+if [[ -f /etc/redhat-release ]]; then
+    # RHEL-variant logic
+    if [[ "$1" = "0" ]]; then
+	# InfluxDB is no longer installed, remove from init system
+	rm -f /etc/default/telegraf
+	
+	which systemctl &>/dev/null
+	if [[ $? -eq 0 ]]; then
+	    disable_systemd
+	else
+	    # Assuming sysv
+	    disable_chkconfig
+	fi
+    fi
+elif [[ -f /etc/debian_version ]]; then
+    # Debian/Ubuntu logic
+    if [[ "$1" != "upgrade" ]]; then
+	# Remove/purge
+	rm -f /etc/default/telegraf
+	
+	which systemctl &>/dev/null
+	if [[ $? -eq 0 ]]; then
+	    disable_systemd
+	else
+	    # Assuming sysv
+	    disable_update_rcd
+	fi
+    fi
+fi