This fixes assertion error which occurs when redirect is done with 0
length body via HTTP/2, and the easy handle is reused, but new
connection is established due to hostname change:

    curl: http2.c:1572: ssize_t http2_recv(struct connectdata *,
      int, char *, size_t, CURLcode *):
    Assertion `httpc->drain_total >= data->state.drain' failed.

To fix this bug, ensure that http2_handle_stream is called.

Fixes #1286
Closes #1302

Assisted-by: Ray Satiro

Bug: https://curl.haxx.se/mail/lib-2017-03/0009.html

Bug: https://github.com/curl/curl/issues/1308
Reported-by: Justin Clift

... because it causes confusion with users. Example URLs:

"http://[127.0.0.1]:11211:80" which a lot of languages' URL parsers will
parse and claim uses port number 80, while libcurl would use port number
11211.

"http://user@example.com:80@localhost" which by the WHATWG URL spec will
be treated to contain user name 'user@example.com' but according to
RFC3986 is user name 'user' for the host 'example.com' and then port 80
is followed by "@localhost"

Both these formats are now rejected, and verified so in test 1260.

Reported-by: Orange Tsai

Closes #1312

Reported-by: Peter Pentchev

Reported-by: Giuseppe Persico

Pointed-out-by: Ray Satiro
Bug: https://curl.haxx.se/mail/lib-2017-03/0004.html

Ref: https://github.com/curl/curl/pull/1228

Ref: https://github.com/curl/curl/pull/1228

Assisted-by: Simon Warta <simon@kullo.net>
Ref: https://github.com/curl/curl/pull/1228

This is closer to how configure.ac does it

Ref: https://github.com/curl/curl/pull/1228

.. also document that CURLE_NOT_BUILT_IN is a RETURN VALUE.

Ref: https://github.com/curl/curl/pull/1290

MSVC with LTCG detects this at warning level 4.

Closes #1304

Move the proxy parse/init into helper create_conn_helper_init_proxy to
mitigate the chances some non-proxy code will be mistakenly added to it.

Ref: https://github.com/curl/curl/issues/1274#issuecomment-281556510
Ref: https://github.com/curl/curl/pull/1293

Closes https://github.com/curl/curl/pull/1298

Mark intended fallthroughs with /* FALLTHROUGH */ so that gcc will know
it's expected and won't warn on [-Wimplicit-fallthrough=].

Closes https://github.com/curl/curl/pull/1297

Prior to this change if you attempted to configure curl using
--wtih-zlib and specified a path the path would be ignored if you also
had pkg-config installed on your system.  This situation can easily
arise when you are cross compiling.  This change moves the test for
detecting zlib settings via pkg-config only if OPT_ZLIB is not set.

Closes https://github.com/curl/curl/pull/1292

Closes https://github.com/curl/curl/pull/1301

Better handle options conflicts that can occur if --enable-pthreads.

Bug: https://github.com/curl/curl/pull/1295
Reported-by: Marc-Antoine Perennou

In DarwinSSL the SSLSetPeerDomainName function is used to enable both
sending SNI and verifying the host. When host verification is disabled
the function cannot be called, therefore SNI is disabled as well.

Closes https://github.com/curl/curl/pull/1240

If size_t is 32 bits, MSVC warns:
warning C4310: cast truncates constant value
The warning is harmless as CURL_MASK_SCOFFT gets
truncated to the maximum value of size_t.

MSVC complains:
warning C4701: potentially uninitialized local variable 'output_token_len' used

wolfSSL >= 3.6.0 supports getting its library version string at runtime.

This is likely to be the case when building from a tar ball release
package which includes a prebuilt man page. In that case, test the
packaged man page instead. This only makes a difference when building
out-of-tree (in-tree, the location in both cases is identical).

Prior to this change if curl was built with Unix Socket support
(--enable-unix-sockets) and without Proxy support (--disable-proxy) then
unix socket options would erroneously be ignored.

Regression introduced in:
0b8d682f

Bug: https://github.com/curl/curl/issues/1274


Reported-by:  <mccormickt12@users.noreply.github.com>

Closes https://github.com/curl/curl/pull/1289

Make use of macro substitution of suffix patterns to remove duplication
of manual names. This approach is portable according to
http://pubs.opengroup.org/onlinepubs/009695399/utilities/make.html

Closes https://github.com/curl/curl/pull/1287

The character set in POSIX is set by the locale defined by (in
decreasing order of precedence) the LC_ALL, LC_CTYPE and LANG
environment variables (CHARSET was used by libidn but not libidn2).
LC_ALL is cleared to ensure that LC_CTYPE takes effect, but LC_ALL is
not used to set the locale to ensure that other parts of the locale
aren't overridden.  Since there doesn't seem to be a cross-platform way
of specifying a UTF-8 locale, and not all systems may support UTF-8, a
<precheck> is used to skip the test if UTF-8 can't be verified to be
available.  Test 1035 was also converted to UTF-8 for consistency, as
the actual character set used there is irrelevant to the test.

This patch uses a different UTF-8 locale than the last attempt, namely
en_US.UTF-8. This one has been verified on 7 different Linux and BSD
distributions and is more complete and usable than the locale UTF-8 (on
at least some systems).

- Change the encoding of the regex temp placeholder token to UTF-8.

Prior to this change the file contained special chars in a different
encoding than ASCII or UTF-8 making text editors and Python complain
when reading the file.

Closes https://github.com/curl/curl/pull/1271
Closes https://github.com/curl/curl/pull/1275