Allow easy opt-out of using start-stop-daemon

Allow users to easily opt-opt of using the start-stop-daemon in the
launch script. This may be required on distros that include older
versions.

Fixes gh-4732

spring-boot-docs/src/main/asciidoc/deployment.adoc

@@ -548,9 +548,14 @@ Gradle and to `${project.description}` (falling back to `${project.name}`) for M
 
 |`initInfoChkconfig`
 |The `chkconfig` section of "`INIT INFO`". Defaults to `2345 99 01`.
+
+|`useStartStopDaemon`
+|If the start-stop command should be used to control the process when it's available.
+ Defaults to `true`.
 |===
 
 
+
 [[deployment-script-customization-conf-file]]
 ==== Customizing the startup script with a conf file
 

spring-boot-tools/spring-boot-loader-tools/src/main/resources/org/springframework/boot/loader/tools/launch.script

@@ -143,7 +143,7 @@ do_start() {
     chown "$run_user" "$PID_FOLDER"
     chown "$run_user" "$pid_file"
     chown "$run_user" "$log_file"
-    if which start-stop-daemon >/dev/null; then
+    if [ {{useStartStopDaemon:true}} = true ] && which start-stop-daemon >/dev/null; then
       start-stop-daemon --start --quiet \
         --chuid $run_user \
         --name $identity \