Remove dead code/comment (#2580)

* Remove dead function that nobody should be using.
Fix comment.
Close #2199

* Log warning if stream option is used.
Close #2199

kernels/PipelineKernel.cpp

@@ -68,6 +68,10 @@ void PipelineKernel::validateSwitches(ProgramArgs& args)
 
     if (m_inputFile.empty())
         throw pdal_error("Input filename required.");
+
+    if (m_stream)
+        m_log->get(LogLevel::Warning) << "Option 'stream' is obsolete.  " <<
+            "Streaming occurs by default.\n";
 }
 
 

pdal/PipelineManager.hpp

@@ -99,12 +99,8 @@ class PDAL_DLL PipelineManager
         Stage& parent, Options options);
     Stage& makeWriter(StageCreationOptions& ops);
 
-    // returns true if the pipeline endpoint is a writer
-    bool isWriterPipeline() const
-        { return (bool)getStage(); }
-
-    // return the pipeline reader endpoint (or nullptr, if not a reader
-    // pipeline)
+    // Return the first leaf stage of a pipeline, or nullptr if the pipeline
+    // is empty.
     Stage* getStage() const
     {
         const auto& llist = leaves();