Update source to SDL2 2.0.12

Edward Rudd

2020-05-02 03f8528315fa46c95991a34f3325d7b33ae5538c

 source/VisualC/SDLtest/SDLtest.vcxproj

@@ -108,7 +108,6 @@
      <StringPooling>true</StringPooling>

      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>

      <BufferSecurityCheck>false</BufferSecurityCheck>

      <EnableEnhancedInstructionSet>StreamingSIMDExtensions</EnableEnhancedInstructionSet>

      <WarningLevel>Level3</WarningLevel>

      <DebugInformationFormat>OldStyle</DebugInformationFormat>

      <OmitDefaultLibName>true</OmitDefaultLibName>

@@ -143,7 +142,6 @@
      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>

      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>

      <BufferSecurityCheck>false</BufferSecurityCheck>

      <EnableEnhancedInstructionSet>StreamingSIMDExtensions</EnableEnhancedInstructionSet>

      <WarningLevel>Level3</WarningLevel>

      <DebugInformationFormat>OldStyle</DebugInformationFormat>

      <OmitDefaultLibName>true</OmitDefaultLibName>