remove the jline flag and automatically detect it

bin/elasticsearch.bat

@@ -52,8 +52,6 @@ REM space for a full heap dump.
 REM JAVA_OPTS=%JAVA_OPTS% -XX:HeapDumpPath=$ES_HOME/logs/heapdump.hprof
 
 
-set JAVA_OPTS=%JAVA_OPTS% -Djline.enabled=false
-
 set ES_CLASSPATH=%CLASSPATH%;%ES_HOME%/lib/elasticsearch-0.16.0-SNAPSHOT.jar;%ES_HOME%/lib/*;%ES_HOME%/lib/sigar/*
 set ES_PARAMS=-Delasticsearch -Des-foreground=yes -Des.path.home="%ES_HOME%"
 

bin/elasticsearch.in.sh

@@ -17,8 +17,6 @@ JAVA_OPTS="$JAVA_OPTS -Xmx${ES_MAX_MEM}"
 # reduce the per-thread stack size
 JAVA_OPTS="$JAVA_OPTS -Xss128k"
 
-JAVA_OPTS="$JAVA_OPTS -Djline.enabled=true"
-
 # Enable aggressive optimizations in the JVM
 #    - Disabled by default as it might cause the JVM to crash
 # JAVA_OPTS="$JAVA_OPTS -XX:+AggressiveOpts"

modules/elasticsearch/src/main/java/org/elasticsearch/bootstrap/Bootstrap.java

@@ -142,6 +142,11 @@ public class Bootstrap {
         Bootstrap bootstrap = new Bootstrap();
         String pidFile = System.getProperty("es-pidfile");
 
+        // enable jline by default when running form "main"
+        if (System.getProperty("jline.enabled") == null) {
+            System.setProperty("jline.enabled", "true");
+        }
+
         boolean foreground = System.getProperty("es-foreground") != null;
         // handle the wrapper system property, if its a service, don't run as a service
         if (System.getProperty("wrapper.service", "XXX").equalsIgnoreCase("true")) {