ENH: Updating doc and warning to reflect new configuration handling

Modules/Core/Common/include/otbConfigurationManager.h

@@ -64,7 +64,7 @@ public:
    *
    * If environment variable OTB_MAX_RAM_HINT is defined and could be
    * converted to int, return its content as a 64 bits unsigned int.
-   * Else, returns 0. 
+   * Else, returns default value, which is 128 Mb 
    *
    */
   static RAMValueType GetMaxRAMHint();

Modules/IO/ImageIO/include/otbImageFileWriter.txx

@@ -310,7 +310,7 @@ ImageFileWriter<TInputImage>
         }
       if(sizevalue == 0.)
         {
-        itkWarningMacro("sizemode is auto but sizevalue is 0. Value will be fetched from configuration file if any, or from cmake configuration otherwise.");
+        itkWarningMacro("sizemode is auto but sizevalue is 0. Value will be fetched from the OTB_MAX_RAM_HINT environment variable if set, or else use the default value");
         }
       this->SetAutomaticAdaptativeStreaming(sizevalue);
       }
@@ -320,7 +320,7 @@ ImageFileWriter<TInputImage>
         {
         if(sizevalue == 0.)
           {
-          itkWarningMacro("sizemode is auto but sizevalue is 0. Value will be fetched from configuration file if any, or from cmake configuration otherwise.");
+          itkWarningMacro("sizemode is auto but sizevalue is 0. Value will be fetched from the OTB_MAX_RAM_HINT environment variable if set, or else use the default value");
           }
         this->SetAutomaticTiledStreaming(sizevalue);
         }