Fix include and library paths for at least me

Despite that the HKLM/SOFTWARE/Microsoft/Microsoft SDKs/Windows/
v10.0/ProductVersion value is 10.0.15063, the headers and libraries we
want are in the subdirectories called 10.0.14393.0, not 10.0.15063.0.

Not sure if this is just because of the collection of Visual Studio
versions I happen to have installed, and their order of installation,
or always true.

Instead of all the convoluted logic in configure.ac, it would make
much more sense to just use the relevant vcvars64.bat or vcvars32.bat
file and pick out the INCLUDE and LIB environment variables it sets,
and mangle that. We already have a (misleadingly named) function to
look for variables set by a .bat file, win_get_env_from_vsvars32bat().

Change-Id: I647ec1d0924ba4c743e4c16d2fa0a05014e0b2e3
diff --git a/configure.ac b/configure.ac
index 8398aa3..49480e8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3325,6 +3325,9 @@ find_ucrt()
            PathFormat "$(win_get_env_from_vsvars32bat UniversalCRTSdkDir)"
            UCRTSDKDIR=$formatted_path
            UCRTVERSION=$(win_get_env_from_vsvars32bat UCRTVersion)
            if test "$UCRTVERSION" = 10.0.15063.0; then
                UCRTVERSION=10.0.14393.0
            fi
        else
          AC_MSG_ERROR([No UCRT found])
        fi
@@ -5191,6 +5194,8 @@ find_winsdk_version()
            winsdklibsubdir=$regvalue
            if test "$regvalue" = "10.0.14393"; then
                winsdklibsubdir="10.0.14393.0"
            elif test "$regvalue" = "10.0.15063"; then
                winsdklibsubdir="10.0.14393.0"
            fi
            return
        fi
@@ -5201,7 +5206,7 @@ find_winsdk_version()
find_winsdk()
{
    # Args: $1 (optional) : list of acceptable SDK versions
    # Return value: $winsdktest
    # Return value: From find_winsdk_version

    unset winsdktest