A regression brought in cb4e2be7

Reported-by: Michael Kaufmann
Bug: https://github.com/curl/curl/issues/1174#issuecomment-274018791

When using multi, mbedtls handshake is in non blocking mode.  vtls must
set wait for read/write flags for the socket.

Closes #1223

Replace use of fixed macro BUFSIZE to define the size of the receive
buffer.  Reappropriate CURLOPT_BUFFERSIZE to include enlarging receive
buffer size.  Upon setting, resize buffer if larger than the current
default size up to a MAX_BUFSIZE (512KB). This can benefit protocols
like SFTP.

Closes #1222

Reported-by: Gisle Vanem

This has been implemented with commit 9ad034e5.

Closes https://github.com/curl/curl/pull/1217

Implemented since curl-7_36_0-130-g8868a226

Reported-by: Fahim Chandurwala

Fix compile warnings that appeared only when curl has been configured
with '--disable-verbose'.

Regression since 1d4202ad, which moved the buffer into a more narrow
scope, but the data in that buffer was used outside of that more narrow
scope.

Reported-by: Dan Fandrich
Bug: https://curl.haxx.se/mail/lib-2017-01/0093.html

- Fix logic error in Curl_ossl_random.

Broken a few days ago in 807698db.

By supporting this, subsequent connects would load a lot less data from
disk.

Closes #1110

Ref: https://github.com/curl/curl/pull/1160

Closes #1211

Before:
```
 % src/curl https://sigsegv.ninja/ -v --http2
...
> GET / HTTP/1.1
> Host: sigsegv.ninja
> User-Agent: curl/7.52.2-DEV
> Accept: */*
>
...
```

After:
```
 % src/curl https://sigsegv.ninja/ -v --http2
...
> GET / HTTP/2
> Host: sigsegv.ninja
> User-Agent: curl/7.52.2-DEV
> Accept: */*
>
```

Closes #1200

Even though it is called --fail-early

Closes #1139

curl_addrinfo.c:519:20: error: conversion to ‘curl_socklen_t {aka
unsigned int}’ from ‘long unsigned int’ may alter its value
[-Werror=conversion]

Follow-up to 1d786fae

In addition to unix domain sockets, Linux also supports an
abstract namespace which is independent of the filesystem.

In order to support it, add new CURLOPT_ABSTRACT_UNIX_SOCKET
option which uses the same storage as CURLOPT_UNIX_SOCKET_PATH
internally, along with a flag to specify abstract socket.

On non-supporting platforms, the abstract address will be
interpreted as an empty string and fail gracefully.

Also add new --abstract-unix-socket tool parameter.

Signed-off-by: Isaac Boukris <iboukris@gmail.com>
Reported-by: Chungtsun Li (typeless)
Reviewed-by: Daniel Stenberg
Reviewed-by: Peter Wu
Closes #1197
Fixes #1061

We have higher resolution since 7.52.0

So that only "global" options (verbose mostly) survive into the next
transfer, and the others have to be set again unless default is fine.

Closes #1169

Assisted-by: Tim Rühsen

It made the german ß get converted to ss, IDNA2003 style, and we can't
have that for the .de TLD - a primary reason for our switch to IDNA2008.

Test 165 verifies.

Follow-up to f30cbcac

Closes #1207

Under condition using http_proxy env var, noproxy list was the
combination of --noproxy option and NO_PROXY env var previously. Since
this commit, --noproxy option overrides NO_PROXY environment variable
even if use http_proxy env var.

Closes #1140

If defined CURL_DISABLE_HTTP, detect_proxy() returned NULL. If not
defined CURL_DISABLE_HTTP, detect_proxy() checked noproxy list.

Thus refactor to set proxy to NULL instead of calling detect_proxy() if
define CURL_DISABLE_HTTP, and refactor to call detect_proxy() if not
define CURL_DISABLE_HTTP and the host is not in the noproxy list.

The combination of --noproxy option and http_proxy env var works well
both for proxied hosts and non-proxied hosts.

However, when combining NO_PROXY env var with --proxy option,
non-proxied hosts are not reachable while proxied host is OK.

This patch allows us to access non-proxied hosts even if using NO_PROXY
env var with --proxy option.

References: http://unicode.org/faq/idn.html
            http://unicode.org/reports/tr46

Closes #1206