Uses a separate build without --enable-debug and no valgrind.

The debug option causes far too many warnings in boringssl's headers
(C++ comments, trailing commas etc).  Valgrind triggers some false
positive errors in thread-local data used by boringssl.

Closes #2118

commit d3ab7c5a broke the boringssl build since it doesn't have
RSA_flags(), so we disable that code block for boringssl builds.

Reported-by: W. Mark Kubacki
Fixes #2117

This bit is no longer used. It is not clear what it meant for users to
"init the TLS" in a world with different TLS backends and since the
introduction of multissl, libcurl didn't properly work if inited without
this bit set.

Not a single user responded to the call for users of it:
https://curl.haxx.se/mail/lib-2017-11/0072.html

Reported-by: Evgeny Grin
Assisted-by: Jay Satiro

Fixes #2089
Fixes #2083
Closes #2107

Reported-by: Alex Nichols
Assisted-by: Kamil Dudka and Max Dymond

CVE-2017-8816

Bug: https://curl.haxx.se/docs/adv_2017-11e7.html

The code would previous read beyond the end of the pattern string if the
match pattern ends with an open bracket when the default pattern
matching function is used.

Detected by OSS-Fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=4161

CVE-2017-8817

Bug: https://curl.haxx.se/docs/adv_2017-ae72.html

- Align the array of ssl_backend_data on a max 32 byte boundary.

8 is likely to be ok but I went with 32 for posterity should one of
the ssl_backend_data structs change to contain a larger sized variable
in the future.

Prior to this change (since dev 70f1db32, release 7.56) the connectdata
structure was undersized by 4 bytes in 32-bit builds with ssl enabled
because long long * was mistakenly used for alignment instead of
long long, with the intention being an 8 byte boundary. Also long long
may not be an available type.

The undersized connectdata could lead to oob read/write past the end in
what was expected to be the last 4 bytes of the connection's secondary
socket https proxy ssl_backend_data struct (the secondary socket in a
connection is used by ftp, others?).

Closes https://github.com/curl/curl/issues/2093

CVE-2017-8818

Bug: https://curl.haxx.se/docs/adv_2017-af0a.html

With this check present, scan-build warns that we might dereference this
point in other places where it isn't first checked for NULL. Thus, if it
*can* be NULL we have a problem on a few places. However, this pointer
should not be possible to be NULL here so I remove the check and thus
also three different scan-build warnings.

Closes #2111

* LOTS of comment updates
* explicit error for SMB shares (e.g. "file:////share/path/file")
* more strict handling of authority (i.e. "//localhost/")
* now accepts dodgy old "C:|" drive letters
* more precise handling of drive letters in and out of Windows
  (especially recognising both "file:c:/" and "file:/c:/")

Closes #2110

Reported by scan-build

Closes #2109

The new API added in Linux 4.11 only requires setting a socket option
before connecting, without the whole sento() machinery.

Notably, this makes it possible to use TFO with SSL connections on Linux
as well, without the need to mess around with OpenSSL (or whatever other
SSL library) internals.

Closes #2056

Fixes #2097
Closes #2108

eg consider a non-existent interface eth8, curl --interface eth8

Before: curl: (45) Could not resolve host: eth8
After: curl: (45) Couldn't bind to 'eth8'

Bug: https://github.com/curl/curl/issues/2104
Reported-by: Alfonso Martone

Fixes #2106
Reported-by: youngchopin on github

Host names like "127.0.0.1 moo" would otherwise be accepted by some
getaddrinfo() implementations.

Updated test 1034 and 1035 accordingly.

Fixes #2073
Closes #2092

Closes #2098

Fixes a scan-build warning.

- Add braces around multi-line if statement.

Closes https://github.com/curl/curl/pull/2096

... so that IPv6 addresses can be passed like they can for connect-to
and how they're used in URLs.

Added test 1324 to verify
Reported-by: Alex Malinovich

Fixes #2087
Closes #2091

The previous fix https://github.com/curl/curl/pull/1788 worked just for
Xcode 9. This commit extends the fix to older Xcode versions effectively
by not using connectx function.

Fixes https://github.com/curl/curl/issues/1330
Fixes https://github.com/curl/curl/issues/2080
Closes https://github.com/curl/curl/pull/1336
Closes #2082

Fixes #2079
Closes #2081

Closes #1455

Follow-up to aadb7c7b. Verified by new test 1263.

Closes #2072

There is a conflict on symbol 'free_func' between openssl/crypto.h and
zlib.h on AIX. This is an attempt to resolve it.

Bug: https://curl.haxx.se/mail/lib-2017-11/0032.html
Reported-By: Michael Felt

Reported-by: Brian Carpenter