Enabled warning level 4 on Visual Studio

This catches uninitialized variables, etc. and matches Steam's warning level

VisualC/SDL/SDL.vcxproj

@@ -112,13 +112,14 @@
       <PreprocessorDefinitions>DLL_EXPORT;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <EnableEnhancedInstructionSet>StreamingSIMDExtensions</EnableEnhancedInstructionSet>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <DebugInformationFormat>OldStyle</DebugInformationFormat>
       <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <PrecompiledHeaderFile>SDL_internal.h</PrecompiledHeaderFile>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <DisableSpecificWarnings>4100;4127;4152;4201</DisableSpecificWarnings>
     </ClCompile>
     <ResourceCompile>
       <PreprocessorDefinitions>_DEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
@@ -143,13 +144,14 @@
       <AdditionalUsingDirectories>%(AdditionalUsingDirectories)</AdditionalUsingDirectories>
       <PreprocessorDefinitions>DLL_EXPORT;_DEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BufferSecurityCheck>false</BufferSecurityCheck>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <DebugInformationFormat>OldStyle</DebugInformationFormat>
       <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <PrecompiledHeaderFile>SDL_internal.h</PrecompiledHeaderFile>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <DisableSpecificWarnings>4100;4127;4152;4201</DisableSpecificWarnings>
     </ClCompile>
     <ResourceCompile>
       <PreprocessorDefinitions>_DEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
@@ -178,13 +180,14 @@
       <PreprocessorDefinitions>DLL_EXPORT;NDEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <EnableEnhancedInstructionSet>StreamingSIMDExtensions</EnableEnhancedInstructionSet>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <PrecompiledHeaderFile>SDL_internal.h</PrecompiledHeaderFile>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <DisableSpecificWarnings>4100;4127;4152;4201</DisableSpecificWarnings>
     </ClCompile>
     <ResourceCompile>
       <PreprocessorDefinitions>NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
@@ -210,13 +213,14 @@
       <AdditionalUsingDirectories>%(AdditionalUsingDirectories)</AdditionalUsingDirectories>
       <PreprocessorDefinitions>DLL_EXPORT;NDEBUG;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BufferSecurityCheck>false</BufferSecurityCheck>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <PrecompiledHeaderFile>SDL_internal.h</PrecompiledHeaderFile>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <DisableSpecificWarnings>4100;4127;4152;4201</DisableSpecificWarnings>
     </ClCompile>
     <ResourceCompile>
       <PreprocessorDefinitions>NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>