ECDH: Add Everest Curve25519 to VS project files

This being the first 3rdparty-contribution, we may want to consider the
structure of the project file generation scripts. Perhaps add small,
constribution-specific scripts to each directory in 3rdparty instead of adding
all constraints to generate_visualc_files.pl?
diff --git a/visualc/VS2010/mbedTLS.vcxproj b/visualc/VS2010/mbedTLS.vcxproj
index 8f4f089..41906f5 100644
--- a/visualc/VS2010/mbedTLS.vcxproj
+++ b/visualc/VS2010/mbedTLS.vcxproj
@@ -87,7 +87,7 @@
       <Optimization>Disabled</Optimization>

       <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;MBEDTLS_EXPORTS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>

-../../include;../../crypto/include

+../../include;../../crypto/include;../../crypto/3rdparty/everest/include/;../../crypto/3rdparty/everest/include/everest;../../crypto/3rdparty/everest/include/everest/vs2010;../../crypto/3rdparty/everest/include/everest/kremlib

       </AdditionalIncludeDirectories>

       <CompileAs>CompileAsC</CompileAs>

     </ClCompile>

@@ -104,7 +104,7 @@
       <Optimization>Disabled</Optimization>

       <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;MBEDTLS_EXPORTS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>

-../../include;../../crypto/include

+../../include;../../crypto/include;../../crypto/3rdparty/everest/include/;../../crypto/3rdparty/everest/include/everest;../../crypto/3rdparty/everest/include/everest/vs2010;../../crypto/3rdparty/everest/include/everest/kremlib

       </AdditionalIncludeDirectories>

       <CompileAs>CompileAsC</CompileAs>

     </ClCompile>

@@ -123,7 +123,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>

       <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;MBEDTLS_EXPORTS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>

-../../include;../../crypto/include

+../../include;../../crypto/include;../../crypto/3rdparty/everest/include/;../../crypto/3rdparty/everest/include/everest;../../crypto/3rdparty/everest/include/everest/vs2010;../../crypto/3rdparty/everest/include/everest/kremlib

       </AdditionalIncludeDirectories>

     </ClCompile>

     <Link>

@@ -143,7 +143,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>

       <PreprocessorDefinitions>WIN64;NDEBUG;_WINDOWS;_USRDLL;MBEDTLS_EXPORTS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>

-../../include;../../crypto/include

+../../include;../../crypto/include;../../crypto/3rdparty/everest/include/;../../crypto/3rdparty/everest/include/everest;../../crypto/3rdparty/everest/include/everest/vs2010;../../crypto/3rdparty/everest/include/everest/kremlib

       </AdditionalIncludeDirectories>

     </ClCompile>

     <Link>