Move backward compatibility aliases to their own header

Move backward compatibility aliases to a separate header. Reserve
crypto_extra.h for implementation-specific extensions that we intend
to keep supporting.

This is better documentation for users. New users should simply ignore
backward compatibility aliases, and old users can look at
crypto_compat.h to see what is deprecated without bothering about new
features appearing in crypto_extra.h.

This facilitates maintenance because scripts such as
generate_psa_constants that want to ignore backward compability
aliases can simply exclude crypto_compat.h from their parsing.
diff --git a/visualc/VS2010/mbedTLS.vcxproj b/visualc/VS2010/mbedTLS.vcxproj
index 7f71a5a..0e40e35 100644
--- a/visualc/VS2010/mbedTLS.vcxproj
+++ b/visualc/VS2010/mbedTLS.vcxproj
@@ -212,6 +212,7 @@
     <ClInclude Include="..\..\include\mbedtls\xtea.h" />

     <ClInclude Include="..\..\include\psa\crypto.h" />

     <ClInclude Include="..\..\include\psa\crypto_accel_driver.h" />

+    <ClInclude Include="..\..\include\psa\crypto_compat.h" />

     <ClInclude Include="..\..\include\psa\crypto_driver_common.h" />

     <ClInclude Include="..\..\include\psa\crypto_entropy_driver.h" />

     <ClInclude Include="..\..\include\psa\crypto_extra.h" />