STYLE: In code examples, use auto for variables initialized by New()

In accordance with the ITK Coding Style, section The auto Keyword:

> The `auto` keyword should be used to specify a type in the following cases:
> -  The type is duplicated on the left side of an initialization when
>    it is mandated on the right side, e.g. when there is an explicit
>    cast or initializing with `new` or ITK's `::New()`.
...

Suggested by Jon Haitz Legarreta Gorroño as part of the review of
pull request InsightSoftwareConsortium/ITK#2826
"STYLE: Use `auto` for declaration of variables initialized by `New()`"

SoftwareGuide/Latex/Appendices/CodingStyleGuide.tex

@@ -915,7 +915,7 @@ \subsubsection{Temporary Variable Naming}
 // on into a temporary image to  use as the input to the mini-pipeline. This
 // avoids a complete copy of the image.
 typename OutputImageType::Pointer output = this->GetOutput();
-typename OutputImageType::Pointer tmp = OutputImageType::New();
+auto                              tmp = OutputImageType::New();
 tmp->SetRequestedRegion( output->GetRequestedRegion() );
 tmp->SetBufferedRegion( output->GetBufferedRegion() );
 tmp->SetLargestPossibleRegion( output->GetLargestPossibleRegion() );
@@ -2069,7 +2069,7 @@ \subsection{Indentation and Tabs}
   this->AllocateOutputs();
 
   // Create a process accumulator for tracking the progress of this minipipeline.
-  ProgressAccumulator::Pointer progress = ProgressAccumulator::New();
+  auto progress = ProgressAccumulator::New();
   progress->SetMiniPipelineFilter( this );
 
   ...
@@ -2825,7 +2825,7 @@ \subsection{Empty Lines}
 
   // Write the output
   using WriterType = itk::ImageFileWriter< OutputImageType >;
-  WriterType::Pointer writer = WriterType::New();
+  auto writer = WriterType::New();
   writer->SetFileName( argv[2] );
   writer->SetInput( hMinimaFilter->GetOutput() );
 

SoftwareGuide/Latex/Architecture/SystemOverview.tex

@@ -255,7 +255,7 @@ \subsection{Smart Pointers and Memory Management}
 
     // here an interpolator is created and associated to the
     // "interp" SmartPointer.
-    InterpolatorType::Pointer interp = InterpolatorType::New();
+    auto interp = InterpolatorType::New();
 
     } /* <------ End of scope */
 \end{minted}
@@ -823,7 +823,7 @@ \section{Wrapping}
 
   using ImageType = itk::Image< PixelType, Dimension >;
   using ReaderType = itk::ImageFileReader< ImageType >;
-  ReaderType::Pointer reader = ReaderType::New();
+  auto reader = ReaderType::New();
   reader->SetFileName( inputImage );
 
   using StructuringElementType = itk::FlatStructuringElement< Dimension >;