Log Message:
curl: update to 7.56.0.

Curl and libcurl 7.56.0

This release includes the following changes:

 o curl: enable compression for SCP/SFTP with --compressed-ssh  [11]
 o libcurl: enable compression for SCP/SFTP with CURLOPT_SSH_COMPRESSION [11]
 o vtls: added dynamic changing SSL backend with curl_global_sslset() [28]
 o new MIME API, curl_mime_init() and friends [32]
 o openssl: initial SSLKEYLOGFILE implementation [36]

This release includes the following bugfixes:

 o FTP: zero terminate the entry path even on bad input [67]
 o examples/ftpuploadresume.c: use portable code
 o runtests: match keywords case insensitively
 o travis: build the examples too [1]
 o strtoofft: reduce integer overflow risks globally [2]
 o zsh.pl: produce a working completion script again [3]
 o cmake: remove dead code for CURL_DISABLE_RTMP [4]
 o progress: Track total times following redirects [5]
 o configure: fix --disable-threaded-resolver [6]
 o cmake: remove dead code for DISABLED_THREADSAFE [7]
 o configure: fix clang version detection
 o darwinssi: fix error: variable length array used
 o travis: add metalink to some osx builds [8]
 o configure: check for __builtin_available() availability [9]
 o http_proxy: fix build error for CURL_DOES_CONVERSIONS [10]
 o examples/ftpuploadresume: checksrc compliance
 o ftp: fix CWD when doing multicwd then nocwd on same connection [12]
 o system.h: remove all CURL_SIZEOF_* defines [13]
 o http: Don't wait on CONNECT when there is no proxy [14]
 o system.h: check for __ppc__ as well [15]
 o http2_recv: return error better on fatal h2 errors [16]
 o scripts/contri*sh: use "git log --use-mailmap"
 o tftp: fix memory leak on too long filename [17]
 o system.h: fix build for hppa [18]
 o cmake: enable picky compiler options with clang and gcc [19]
 o makefile.m32: add support for libidn2 [20]
 o curl: turn off MinGW CRT's globbing [21]
 o request-target.d: mention added in 7.55.0
 o curl: shorten and clean up CA cert verification error message [22]
 o imap: support PREAUTH [23]
 o CURLOPT_USERPWD.3: see also CURLOPT_PROXYUSERPWD
 o examples/threaded-ssl: mention that this is for openssl before 1.1
 o winbuild: fix embedded manifest option [24]
 o tests: Make sure libtests & unittests call curl_global_cleanup()
 o system.h: include sys/poll.h for AIX [25]
 o darwinssl: handle long strings in TLS certs [26]
 o strtooff: fix build for systems with long long but no strtoll [27]
 o asyn-thread: Improved cleanup after OOM situations
 o HELP-US.md: "How to get started helping out in the curl project" [29]
 o curl.h: CURLSSLBACKEND_WOLFSSL used wrong value [30]
 o unit1301: fix error message on first test
 o ossfuzz: moving towards the ideal integration [31]
 o http: fix a memory leakage in checkrtspprefix()
 o examples/post-callback: stop returning one byte at a time
 o schannel: return CURLE_SSL_CACERT on failed verification [33]
 o MAIL-ETIQUETTE: added "1.9 Your emails are public"
 o http-proxy: treat all 2xx as CONNECT success [34]
 o openssl: use OpenSSL's default ciphers by default [35]
 o runtests.pl: support attribute "nonewline" in part verify/upload
 o configure: remove --enable-soname-bump and SONAME_BUMP [37]
 o travis: add c-ares enabled builds linux + osx [38]
 o vtls: fix WolfSSL 3.12 build problems [39]
 o http-proxy: when not doing CONNECT, that phase is done immediately [40]
 o configure: fix curl_off_t check's include order [41]
 o configure: use -Wno-varargs on clang 3.9[.X] debug builds
 o rtsp: do not call fwrite() with NULL pointer FILE * [42]
 o mbedtls: enable CA path processing [43]
 o travis: add build without HTTP/SMTP/IMAP
 o checksrc: verify more code style rules [44]
 o HTTP proxy: on connection re-use, still use the new remote port [45]
 o tests: add initial gssapi test using stub implementation [46]
 o rtsp: Segfault when using WRITEDATA [47]
 o docs: clarify the CURLOPT_INTERLEAVE* options behavior
 o non-ascii: use iconv() with 'char **' argument [48]
 o server/getpart: provide dummy function to build conversion enabled
 o conversions: fix several compiler warnings
 o openssl: add missing includes [49]
 o schannel: Support partial send for when data is too large [50]
 o socks: fix incorrect port number in SOCKS4 error message [51]
 o curl: fix integer overflow in timeout options [52]
 o travis: on mac, don't install openssl or libidn [53]
 o cookies: reject oversized cookies instead of truncating [54]
 o cookies: use lock when using CURLINFO_COOKIELIST [55]
 o curl: check fseek() return code and bail on error
 o examples/post-callback: use long for CURLOPT_POSTFIELDSIZE
 o openssl: only verify RSA private key if supported [56]
 o tests: make the imap server not verify user+password [57]
 o imap: quote atoms properly when escaping characters [58]
 o tests: fix a compiler warning in test 643
 o file_range: avoid integer overflow when figuring out byte range [59]
 o curl.h: include <sys/select.h> on cygwin too [60]
 o reuse_conn: don't copy flags that are known to be equal [61]
 o http: fix adding custom empty headers to repeated requests [62]
 o docs: clarify the use of environment variables for proxy [63]
 o docs: link CURLOPT_CONNECTTIMEOUT and CURLOPT_CONNECTTIMEOUT_MS [64]
 o connect: fix race condition with happy eyeballs timeout [65]
 o cookie: fix memory leak if path was set twice in header [66]
 o vtls: compare and clone ssl configs properly [68]
 o proxy: read the "no_proxy" variable only if necessary [69]