Closes https://github.com/curl/curl/pull/1671

Ref: #1591

ldap_bind_s is marked as deprecated in w32api's winldap.h shipping with
the latest original MinGW, resulting in compiler warnings since commit
f0fe66f1. Fix this for the non-SSPI
case by using ldap_simple_bind_s again instead of ldap_bind_s with
LDAP_AUTH_SIMPLE.

Closes https://github.com/curl/curl/pull/1664

When building with Cygwin or MinGW, libtool uses a wrapper executable
instead of a wrapper script [1], which is written in C and throws
missing-variable-declarations warnings. Don't enable these warnings on
Cygwin and MinGW in order to avoid warnings for every executable built,
which spams the test suite output when using Cygwin's clang.

[1] https://www.gnu.org/software/libtool/manual/html_node/Wrapper-executables.html

Closes https://github.com/curl/curl/pull/1665

Prior to this change (SET_)ERRNO mapped to GetLastError/SetLastError
for Win32 and regular errno otherwise.

I reviewed the code and found no justifiable reason for conflating errno
on WIN32 with GetLastError/SetLastError. All Win32 CRTs support errno,
and any Win32 multithreaded CRT supports thread-local errno.

Fixes https://github.com/curl/curl/issues/895
Closes https://github.com/curl/curl/pull/1589

GCC 4.6.3 on travis complains:
smb.c: In function ‘get_posix_time’:
smb.c:725:13: error: declaration of ‘time’ shadows a global declaration
[-Werror=shadow]

Fix this by renaming the variable.

GCC 4.4 complains:
tool_cb_wrt.c:81: error: declaration of ‘isatty’ shadows a global
declaration
/usr/include/unistd.h:782: error: shadowed declaration is here

Fix this by renaming the variable.

Closes https://github.com/curl/curl/pull/1661

Closes #1653

Removes BUILD_RELEASE_DEBUG_DIRS since it wasn't used anywhere.

Closes #1649

Add a basic telnet server for negotiating some telnet options before
echoing back any data that's sent to it.

Closes #1645

I added a selection of torture and event tests that run "fast enough"

Fixes #1612
Reported-by: Jeroen Ooms

Bug: https://github.com/curl/curl/issues/828#issuecomment-313475151

Fixes #1552

... to let tests require it or skip if present

Make the name reflect its use better, and add a short comment describing
what it's for.

... and make sure inet_pton is always checked for when *not* using Windows,
which is a regression from 4fc6ebe1.

Idea-by: Sergei Nikulov

... by checking the POLLIN define, as the header file checks don't work
on Windows.

inet_pton() exists on Windows and gets used by our cmake builds. Make
sure the correct header file is included to avoid compiler warnings.

Closes #1639

Closes #1572

... by simply trying the Windows argument types first.

Fixes #1640

Bug: https://curl.haxx.se/mail/lib-2017-07/0005.html

Closes #1643

Closes #1642

bug: https://curl.haxx.se/mail/lib-2017-07/0005.html

When scanning for which LDAP libraries to use, try the -lldap -llber
combination before the reversed order since it has a greater chance of
working when linking with libcurl statically.

Fixes #1619
Closes #1634
Reported-by: David E. Narváez

fork, getprotobyname, inet_addr, perror, uname

closes #1638