Libelektra: crypto_botan：botan 2.13 标头弃用警告

从 botan 2.13.x（也许更早？）开始，我们开始收到以下标头弃用警告：

In file included from ../src/plugins/crypto/botan_operations.cpp:12:
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/hmac.h:14:1: warning: this header will be made internal in the future [-W#pragma-messages]
BOTAN_FUTURE_INTERNAL_HEADER(hmac.h)
^
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/compiler.h:107:49: note: expanded from macro 'BOTAN_FUTURE_INTERNAL_HEADER'
      #define BOTAN_FUTURE_INTERNAL_HEADER(hdr) _Pragma("message \"this header will be made internal in the future\"")
                                                ^
<scratch space>:100:2: note: expanded from here
 message "this header will be made internal in the future"
 ^
In file included from ../src/plugins/crypto/botan_operations.cpp:13:
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/init.h:16:1: warning: this header is deprecated [-W#pragma-messages]
BOTAN_DEPRECATED_HEADER(init.h)
^
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/compiler.h:104:42: note: expanded from macro 'BOTAN_DEPRECATED_HEADER'
    #define BOTAN_DEPRECATED_HEADER(hdr) _Pragma("message \"this header is deprecated\"")
                                         ^
<scratch space>:102:2: note: expanded from here
 message "this header is deprecated"
 ^
In file included from ../src/plugins/crypto/botan_operations.cpp:14:
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/lookup.h:35:1: warning: this header is deprecated [-W#pragma-messages]
BOTAN_DEPRECATED_HEADER(lookup.h)
^
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/compiler.h:104:42: note: expanded from macro 'BOTAN_DEPRECATED_HEADER'
    #define BOTAN_DEPRECATED_HEADER(hdr) _Pragma("message \"this header is deprecated\"")
                                         ^
<scratch space>:104:2: note: expanded from here
 message "this header is deprecated"
 ^
In file included from ../src/plugins/crypto/botan_operations.cpp:15:
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/pbkdf2.h:16:1: warning: this header will be made internal in the future [-W#pragma-messages]
BOTAN_FUTURE_INTERNAL_HEADER(pbkdf2.h)
^
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/compiler.h:107:49: note: expanded from macro 'BOTAN_FUTURE_INTERNAL_HEADER'
      #define BOTAN_FUTURE_INTERNAL_HEADER(hdr) _Pragma("message \"this header will be made internal in the future\"")
                                                ^
<scratch space>:106:2: note: expanded from here
 message "this header will be made internal in the future"
 ^
In file included from ../src/plugins/crypto/botan_operations.cpp:17:
In file included from /usr/local/Cellar/botan/2.13.0/include/botan-2/botan/sha2_32.h:12:
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/mdx_hash.h:13:1: warning: this header will be made internal in the future [-W#pragma-messages]
BOTAN_FUTURE_INTERNAL_HEADER(mdx_hash.h)
^
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/compiler.h:107:49: note: expanded from macro 'BOTAN_FUTURE_INTERNAL_HEADER'
      #define BOTAN_FUTURE_INTERNAL_HEADER(hdr) _Pragma("message \"this header will be made internal in the future\"")
                                                ^
<scratch space>:108:2: note: expanded from here
 message "this header will be made internal in the future"
 ^
In file included from ../src/plugins/crypto/botan_operations.cpp:17:
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/sha2_32.h:14:1: warning: this header will be made internal in the future [-W#pragma-messages]
BOTAN_FUTURE_INTERNAL_HEADER(sha2_32.h)
^
/usr/local/Cellar/botan/2.13.0/include/botan-2/botan/compiler.h:107:49: note: expanded from macro 'BOTAN_FUTURE_INTERNAL_HEADER'
      #define BOTAN_FUTURE_INTERNAL_HEADER(hdr) _Pragma("message \"this header will be made internal in the future\"")
                                                ^
<scratch space>:110:2: note: expanded from here
 message "this header will be made internal in the future"
 ^
6 warnings generated.

Botan 维护着一个已弃用的标题文档。