Add GME to MSVC 10 solution

MSVC builds did not have GME enabled, so I fixed that up real quick.

This flips on HAVE_LIBGME and HAVE_ZLIB for SRB2WIN and SRB2DD. It compiles and works fine on Visual Studio 2015 (target platform 8.1)

r_opengl.dll

fmodexL.dll

Srb2DD-gme.exe

Srb2Win-gme.exe

test_music.wad (tunes gme01)

libs/libgme.props

+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ImportGroup Label="PropertySheets" />
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Platform)' == 'Win32' OR '$(Platform)' == 'x64'">
+    <IncludePath>$(SolutionDir)libs\gme\include;$(IncludePath)</IncludePath>
+    <LibraryPath Condition="'$(Platform)' == 'Win32'">$(SolutionDir)libs\gme\win32;$(LibraryPath)</LibraryPath>
+    <LibraryPath Condition="'$(Platform)' == 'x64'">$(SolutionDir)libs\gme\win64;$(LibraryPath)</LibraryPath>
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Platform)' == 'Win32' OR '$(Platform)' == 'x64'">
+    <Link>
+      <AdditionalDependencies>libgme.dll.a;%(AdditionalDependencies)</AdditionalDependencies>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup />
+</Project>
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