Make exciting improvements

- Add Lua backtraces to redbean!
- Wipe serving keys after redbean forks
- Audit redbean to remove free via exit
- Log SSL client ciphersuite preferences
- Increase ASAN malloc() backtrace depth
- Make GetSslRoots() behave as a singleton
- Move leaks.c from LIBC_TESTLIB to LIBC_LOG
- Add undocumented %n to printf() for newlines
- Fix redbean memory leak reindexing inode change
- Fix redbean memory leak with Fetch() DNS object
- Restore original environ after __cxa_finalize()
- Make backtrace always work after __cxa_finalize()
- Introduce COUNTEXPR() diagnostic / benchmark tool
- Fix a few more instances of errno being clobbered
- Consolidate the ANSI color disabling internal APIs

third_party/mbedtls/ssl.h

@@ -1250,6 +1250,7 @@ struct mbedtls_ssl_context
                             *   Possible values are #MBEDTLS_SSL_CID_ENABLED
                             *   and #MBEDTLS_SSL_CID_DISABLED. */
 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
+  uint16_t client_ciphers[16]; /* [jart] clarifies MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE */
 };
 
 /**