cURL 7.50.0发布，字符界面下载工具

cURL 7.50.0 发布了，cURL是一款著名的字符界面下的下载工具，支持HTTP、HTTPS、FTP、FTPS、DICT、TELNET、LDAP、FILE,和GOPHER。 此外还具有cookies支持、断点续传、FTP上传、密码支持、SSL支持和代理支持等特性。curl同时还提供了一套libcurl的库，开发者可以 基于这个库开发其他下载工具。

本次发布改进日志如下：

Changes:

• http: add CURLINFO_HTTP_VERSION and %{http_version}

Bugfixes:

• memdebug: fix MSVC crash with -DMEMDEBUG_LOG_SYNC

• openssl: fix build with OPENSSL_NO_COMP

• mbedtls: removed unused variables

• cmake: Added missing mbedTLS support

• URL parser: allow URLs to use one, two or three slashes

• curl: fix -q [regression]

• openssl: Use correct buffer sizes for error messages

• curl: fix SIGSEGV while parsing URL with too many globs

• schannel: add CURLOPT_CERTINFO support

• vtls: fix ssl session cache race condition

• http: Fix HTTP/2 connection reuse [regression]

• checksrc: Add LoadLibrary to the banned functions list

• schannel: Disable ALPN on Windows < 8.1

• configure: occasional ignorance of --enable-symbol-hiding with GCC

• http2: test17xx are the first real HTTP/2 tests

• resolve: add support for IPv6 DNS64/NAT64 Networks on OS X + iOS

• curl_multi_socket_action.3: rewording

• CURLOPT_POSTFIELDS.3: Clarify what happens when set empty

• cmake: Fix build with winldap

• openssl: fix cert check with non-DNS name fields present

• curl.1: mention the units for the progress meter

• openssl: use more 'const' to fix build warnings with 1.1.0 branch

• cmake: now using BUILD_TESTING=ON/OFF

• vtls: Only call add/getsession if session id is enabled

• headers: forward declare CURL, CURLM and CURLSH as structs

• configure: improve detection of CA bundle path on FreeBSD

• SFTP: set a generic error when no SFTP one exists

• curl_global_init.3: expand on the SSL and WIN32 bits purpose

• conn: don't free easy handle data in handler->disconnect

• cookie.c: Fix misleading indentation

• library: Fix memory leaks found during static analysis

• CURLMOPT_SOCKETFUNCTION.3: fix typo

• curl_global_init: moved the "IPv6 works" check here

• connect: disable TFO on Linux when using SSL

• vauth: Fixed memory leak due to function returning without free

• winbuild: fix embedded manifest option