Remove obsolete logstash startup messages

Fixes #5571

docs/static/configuration.asciidoc

@@ -519,15 +519,16 @@ Let's see what comes out:
 ----------------------------------
 
 $ bin/logstash -f ../test.conf
-Logstash startup completed
+Pipeline main started
 asdf
 {
-       "message" => "asdf",
+    "@timestamp" => 2016-06-30T02:42:51.496Z,
       "@version" => "1",
-    "@timestamp" => "2015-03-18T23:09:29.595Z",
           "host" => "example.com",
-          "show" => "This data will be in the output"
+          "show" => "This data will be in the output",
+       "message" => "asdf"
 }
+
 ----------------------------------
 
 The "asdf" typed in became the `message` field contents, and the conditional
@@ -548,18 +549,18 @@ Let's see what the output looks like with this change:
 [source,ruby]
 ----------------------------------
 $ bin/logstash -f ../test.conf
-Logstash startup completed
+Pipeline main started
 asdf
 {
-       "message" => "asdf",
-      "@version" => "1",
-    "@timestamp" => "2015-03-18T23:10:19.859Z",
-          "host" => "example.com",
-          "show" => "This data will be in the output",
+    "@timestamp" => 2016-06-30T02:46:48.565Z,
      "@metadata" => {
            "test" => "Hello",
         "no_show" => "This data will not be in the output"
-    }
+    },
+      "@version" => "1",
+          "host" => "example.com",
+          "show" => "This data will be in the output",
+       "message" => "asdf"
 }
 ----------------------------------
 
@@ -600,13 +601,13 @@ configuration a sample date string and see what comes out:
 [source,ruby]
 ----------------------------------
 $ bin/logstash -f ../test.conf
-Logstash startup completed
+Pipeline main started
 02/Mar/2014:15:36:43 +0100
 {
-       "message" => "02/Mar/2014:15:36:43 +0100",
+    "@timestamp" => 2014-03-02T14:36:43.000Z,
       "@version" => "1",
-    "@timestamp" => "2014-03-02T14:36:43.000Z",
-          "host" => "example.com"
+          "host" => "example.com",
+       "message" => "02/Mar/2014:15:36:43 +0100"
 }
 ----------------------------------
 

docs/static/stalled-shutdown.asciidoc

@@ -31,32 +31,25 @@ In this example, slow filter execution prevents the pipeline from clean shutdown
 
 ========
 [source,shell]
-% bin/logstash -e 'input { generator { } } filter { ruby { code => "sleep 10000" } } \
-                     output { stdout { codec => dots } }' -w 1 --pipeline.unsafe_shutdown
-Default settings used: Filter workers: 1
-Logstash startup completed
-^CSIGINT received. Shutting down the pipeline. {:level=>:warn}
+bin/logstash -e 'input { generator { } } filter { ruby { code => "sleep 10000" } } 
+  output { stdout { codec => dots } }' -w 1 --pipeline.unsafe_shutdown
+Pipeline main started
+^CSIGINT received. Shutting down the agent. {:level=>:warn}
+stopping pipeline {:id=>"main", :level=>:warn}
 Received shutdown signal, but pipeline is still waiting for in-flight events
 to be processed. Sending another ^C will force quit Logstash, but this may cause
 data loss. {:level=>:warn}
- {:level=>:warn, "INFLIGHT_EVENT_COUNT"=>{"input_to_filter"=>20, "total"=>20},
- "STALLING_THREADS"=>
- {["LogStash::Filters::Ruby", {"code"=>"sleep 10000"}]=>[{"thread_id"=>15,
- "name"=>"|filterworker.0", "current_call"=>"
- (ruby filter code):1:in `sleep'"}]}}
-The shutdown process appears to be stalled due to busy or blocked plugins. Check
-    the logs for more information.
-{:level=>:error}
- {:level=>:warn, "INFLIGHT_EVENT_COUNT"=>{"input_to_filter"=>20, "total"=>20},
- "STALLING_THREADS"=>
- {["LogStash::Filters::Ruby", {"code"=>"sleep 10000"}]=>[{"thread_id"=>15,
- "name"=>"|filterworker.0", "current_call"=>"
- (ruby filter code):1:in `sleep'"}]}}
- {:level=>:warn, "INFLIGHT_EVENT_COUNT"=>{"input_to_filter"=>20, "total"=>20},
- "STALLING_THREADS"=>
- {["LogStash::Filters::Ruby", {"code"=>"sleep 10000"}]=>[{"thread_id"=>15,
- "name"=>"|filterworker.0", "current_call"=>"
- (ruby filter code):1:in `sleep'"}]}}
+{"inflight_count"=>125, "stalling_thread_info"=>{["LogStash::Filters::Ruby", 
+{"code"=>"sleep 10000"}]=>[{"thread_id"=>19, "name"=>"[main]>worker0", 
+"current_call"=>"(ruby filter code):1:in `sleep'"}]}} {:level=>:warn}
+The shutdown process appears to be stalled due to busy or blocked plugins. 
+Check the logs for more information. {:level=>:error}
+{"inflight_count"=>125, "stalling_thread_info"=>{["LogStash::Filters::Ruby", 
+{"code"=>"sleep 10000"}]=>[{"thread_id"=>19, "name"=>"[main]>worker0", 
+"current_call"=>"(ruby filter code):1:in `sleep'"}]}} {:level=>:warn}
+{"inflight_count"=>125, "stalling_thread_info"=>{["LogStash::Filters::Ruby", 
+{"code"=>"sleep 10000"}]=>[{"thread_id"=>19, "name"=>"[main]>worker0", 
+"current_call"=>"(ruby filter code):1:in `sleep'"}]}} {:level=>:warn}
 Forcefully quitting logstash.. {:level=>:fatal}
 ========