Deprecate ExternalCommandListener feature ('command') and adjust log warnings to the roadmap

They won't be removed with 2.11 thus far. Users should
be guided to the roadmap which holds all details instead
of hardcoding a version in the code.

doc/09-object-types.md

@@ -270,6 +270,11 @@ Configuration Attributes:
 Reads Icinga 1.x check result files from a directory. This functionality is provided
 to help existing Icinga 1.x users and might be useful for migration scenarios.
 
+> **Note**
+>
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
+
 Example:
 
 ```
@@ -319,6 +324,11 @@ Configuration Attributes:
 Writes log files in a format that's compatible with Icinga 1.x.
 This configuration object is available as [compatlog feature](14-features.md#compat-logging).
 
+> **Note**
+>
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
+
 Example:
 
 ```
@@ -599,6 +609,11 @@ More advanced examples for event command usage can be found [here](03-monitoring
 Implements the Icinga 1.x command pipe which can be used to send commands to Icinga.
 This configuration object is available as [command feature](14-features.md#external-commands).
 
+> **Note**
+>
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
+
 Example:
 
 ```
@@ -1558,6 +1573,11 @@ Configuration Attributes:
 Periodically writes status and configuration data files which are used by third-party tools.
 This configuration object is available as [statusdata feature](14-features.md#status-data).
 
+> **Note**
+>
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
+
 Example:
 
 ```

doc/14-features.md

@@ -165,6 +165,11 @@ VACUUM
 > Please use the [REST API](12-icinga2-api.md#icinga2-api) as modern and secure alternative
 > for external actions.
 
+> **Note**
+>
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
+
 Icinga 2 provides an external command pipe for processing commands
 triggering specific actions (for example rescheduling a service check
 through the web interface).
@@ -817,7 +822,8 @@ A detailed list on the available table attributes can be found in the [Livestatu
 
 > **Note**
 >
-> This feature is DEPRECATED and will be removed in Icinga 2 v2.11.
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
 
 Icinga 1.x writes object configuration data and status data in a cyclic
 interval to its `objects.cache` and `status.dat` files. Icinga 2 provides
@@ -835,7 +841,8 @@ you can safely disable this feature.
 
 > **Note**
 >
-> This feature is DEPRECATED and will be removed in Icinga 2 v2.11.
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
 
 The Icinga 1.x log format is considered being the `Compat Log`
 in Icinga 2 provided with the `CompatLogger` object.
@@ -860,7 +867,8 @@ in `/var/log/icinga2/compat`. Rotated log files are moved into
 
 > **Note**
 >
-> This feature is DEPRECATED and will be removed in Icinga 2 v2.11.
+> This feature is DEPRECATED and will be removed in future releases.
+> Check the [roadmap](https://github.com/Icinga/icinga2/milestones).
 
 Icinga 1.x writes its check result files to a temporary spool directory
 where they are processed in a regular interval.

lib/compat/checkresultreader.cpp

@@ -45,7 +45,7 @@ void CheckResultReader::Start(bool runtimeCreated)
 		<< "'" << GetName() << "' started.";
 
 	Log(LogWarning, "CheckResultReader")
-		<< "The CheckResultReader feature is DEPRECATED and will be removed in Icinga v2.11.";
+		<< "This feature is DEPRECATED and will be removed in future releases. Check the roadmap at https://github.com/Icinga/icinga2/milestones";
 
 #ifndef _WIN32
 	m_ReadTimer = new Timer();

lib/compat/compatlogger.cpp

@@ -47,7 +47,7 @@ void CompatLogger::Start(bool runtimeCreated)
 		<< "'" << GetName() << "' started.";
 
 	Log(LogWarning, "CompatLogger")
-		<< "The CompatLogger feature is DEPRECATED and will be removed in Icinga v2.11.";
+		<< "This feature is DEPRECATED and will be removed in future releases. Check the roadmap at https://github.com/Icinga/icinga2/milestones";
 
 	Checkable::OnNewCheckResult.connect(std::bind(&CompatLogger::CheckResultHandler, this, _1, _2));
 	Checkable::OnNotificationSentToUser.connect(std::bind(&CompatLogger::NotificationSentHandler, this, _1, _2, _3, _4, _5, _6, _7, _8));

lib/compat/externalcommandlistener.cpp

@@ -36,6 +36,8 @@ void ExternalCommandListener::Start(bool runtimeCreated)
 	Log(LogInformation, "ExternalCommandListener")
 		<< "'" << GetName() << "' started.";
 
+	Log(LogWarning, "ExternalCommandListener")
+		<< "This feature is DEPRECATED and will be removed in future releases. Check the roadmap at https://github.com/Icinga/icinga2/milestones";
 #ifndef _WIN32
 	m_CommandThread = std::thread(std::bind(&ExternalCommandListener::CommandPipeThread, this, GetCommandPath()));
 	m_CommandThread.detach();

lib/compat/statusdatawriter.cpp

@@ -61,7 +61,7 @@ void StatusDataWriter::Start(bool runtimeCreated)
 		<< "'" << GetName() << "' started.";
 
 	Log(LogWarning, "StatusDataWriter")
-		<< "The StatusDataWriter feature is DEPRECATED and will be removed in Icinga v2.11.";
+		<< "This feature is DEPRECATED and will be removed in future releases. Check the roadmap at https://github.com/Icinga/icinga2/milestones";
 
 	m_ObjectsCacheOutdated = true;