2.5
 - Add curl_echo() function for easy testing
 - Add support for curlopt_xferinfofunction, used in curl_echo()
 - Automatically set curlopt_noprogress = 0 when setting one of the progress functions
 - Automatically use XFERINFOFUNCTION vs PROGRESSFUNCTION depending on libcurl version
 - Default User-Agent is now: options("HTTPUserAgent")
 - Requests will now abort if progress/xferinfo callback raises an error
 - Open a connection with mode 'f' to skip stop_for_status() during open()

2.4
 - Windows: update libcurl to 7.53.1 with libssl 1.0.2k
 - New form_data() function to POST form with string/raw values with custom conten-type
 - Fix busy waiting for curl_fetch_stream()
 - Tweaks for open(con, blocking = FALSE)
 - Switch memcpy() to memmove() to please valgrind
 - Assert that curl() connection is only opened in read mode

2.3
 - All interruptable handles now use a global pool to share connections. Fixes #79.
 - Enable interruptable interface by default, even in non-interactive mode.
 - Update libcurl on Windows to 7.51.0
 - Unit tests now try serveral httpbin mirrors in case one goes down
 - Support open(con, blocking = FALSE) and isIncomplete() for curl() connections
 - Switch curl_fetch_stream to non-blocking implementation

2.2
 - Fixed bug in multi that did not actually enable or disable multiplexing.
 - Switch unit tests to HTTP/2 server to get HTTP/2 testing coverage
 - Fix big endian build on GLIBC systems (tnx Aurelien Jarno and Andreas Tille)

2.1
 - If libcurl >= 7.47 and was built --with-nghttp2, automatically enable HTTP/2
   on HTTPS connections (matches behavior of 'curl' cmd util)
 - Upgrade to libcurl 7.50.3 (--with-nghttp2) on Windows (Adds HTTP/2 support)
 - Fix a unit test that would fail on fast servers

2.0
 - New multi interface for concurrent async requests!
 - Updated vignette with simple multi examples
 - Export handle_data() to get handle state

1.2
 - Fix for getaddrinfo GNU extension on some unix platforms

1.1
 - Fix ASAN warning in curl.c (reference after free)

1.0
 - Fix for FreeBSD
 - Simplify handle refCount system
 - Better handle locking to prevent using/modifying open handles
 - Make unit tests always close connection to prevent 'unused connection' warnings
 - Add support for interruptions in curl_download()

0.9.7
 - The non-blocking download method is now only used in interactive mode
 - Use options(curl_interrupt = TRUE) to force nonblocking in non-interactive mode
 - Updated libcurl on windows to 7.47.1. This should fix IPv6 problems.
 - Update the curl_symbols table to 7.48

0.9.6
 - Use non-blocking code in curl_fetch_memory to support user interruptions.
 - Configure script no longer assumes bash so it works on OpenBSD.
 - Fix for Snow Leopard CRAN build server.
 - Added has_internet() function.

0.9.5
 - Added nslookup() as cross-platform alternative to nsl()

0.9.4
 - Move the creation of the option table to ./R/options.R
 - The curl_options() function gains an argument to filter by name
 - Properly invoke winhttp.def file in Makevars.win (required for new toolchain)

0.9.3
 - Refactor configure script to use pkg-config
 - Use the preprocessor to extract CURLOPT symbols during install
 - Don't use setInternet2() in R > 3.2.2

0.9.2
 - Optimization for windows to make realloc in curl_fetch_memory faster
 - Updated the curl_symbols table to 7.43
 - Updated the static libraries on Windows:
    * libcurl 7.43.0
    * openssl 1.0.2d
    * libssh2 1.6.0
    * libiconv 1.14-5
    * libidn 1.31-1
 - New functions for Windows: ie_proxy_info and ie_get_proxy_for_url

0.9.1
 - Convert url argument to utf8 strings in escape/unescape
 - Endian fix for BSD systems
 - Add support for setting curlopt_xxx_large options

0.9
 - Fix for very old versions of libcurl (RHEL 5)
 - Do not convert paths to UTF-8 (only URLs)
 - Improve error message for unknown options

0.8
 - Fix for curl() character reader to invert byte-order on big endian architectures.

0.7
 - Rename the C function 'fetch' to 'fetchdata' because of Solaris conflict.
 - Move warning about missing CA bundle on Windows to onAttach.

0.6
 - Validation of SSL certificates is now enabled by default if a bundle is available.
 - Major rewrite to support configurable and reusable handles
 - Added new_handle, handle_setopt, handle_setheaders, handle_setform, handle_reset, etc.
 - Added curl_fetch interfaces for httr
 - Add ie_proxy_settings to get system proxy configuration on windows

0.5
 - Check for CURLM_CALL_MULTI_PERFORM to support very old versions of libcurl

0.4
 - Fixed a memory bug that could cause R to crash
 - Add curl_escape, curl_unescape
 - Add curl_version and curl_options

0.3
 - Add curl_download function
 - More efficient use of realloc
 - Fix for older versions of libcurl (e.g. Snow Leopard)
 - Add support for user interrupts while downloading (ESC or CTRL+C)
 - Fixed bug that caused GC to corrupt connection object
 - Refactoring and cleanup

0.2
  - add support for recycling connections

0.1
  - initial release
