Follow-up to 34634080.

Prior to 34634080 file:// hostnames were silently stripped.

Prior to this commit it did not work when a schemeless url was used with
file as the default protocol.

Ref: https://curl.haxx.se/mail/lib-2016-11/0081.html
Closes https://github.com/curl/curl/pull/1124

Also fix for drive letters:

- Support --proto-default file c:/foo/bar.txt

- Support file://c:/foo/bar.txt

- Fail when a file:// drive letter is detected and not MSDOS/Windows.

Bug: https://github.com/curl/curl/issues/1187
Reported-by: Anatol Belski
Assisted-by: Anatol Belski

Regression introduced in commit f682156a

Reported-by: John Kohl
Bug: https://curl.haxx.se/mail/lib-2017-01/0055.html

Both IMAP and POP3 response characters are used internally, but when
appended to the STARTTLS denial message likely could confuse the user.

Closes https://github.com/curl/curl/pull/1203

- Format the numeric denial code as an integer instead of a character.

... when checking for a too large request.

Define _WINSOCKAPI_ blank rather than to 1 in order to match the value
used by Microsoft's winsock header files.

Closes https://github.com/curl/curl/pull/1195

Fixes spurious test 1060 and 1061 failures on OpenBSD, Solaris and more.

Bug: https://curl.haxx.se/mail/lib-2017-01/0009.html
Reported-by: Christian Weisgerber

At least mostly, not counting // comments.

libcurl requires CURLMOPT_SOCKETFUNCTION to KEEP watching socket events
and notify back. Modify event_cb() to continue watching events when
fired.

Fixes #1191
Closes #1192
Fixed-by: Mingliang Zhu

Rename symbol lock to locks to not clash with OW CRTL function name.

Closes #1196

Removed items already fixed, clarified a few others.

Reported in #1190
Reported-by: Dan Jacobson

curl.1 is regenerated

Fixes #1190

Fixes #1184

Since the TCP keep-alive options were added in 705f0f7a the start and
interval default values have been 60, but that wasn't documented.

Bug: https://curl.haxx.se/mail/lib-2017-01/0000.html
Reported-by: Praveen Pvs

This error code was once introduced when some library was dynamically
loaded and a funciton within said library couldn't be found.

Failure to decompress is now a write error instead of the weird
"function not found".

- Use Windows API SetFileTime to set the file time instead of utime.

Avoid utime on Windows if possible because it may apply a daylight
saving time offset to our UTC file time.

Bug: https://curl.haxx.se/mail/archive-2016-11/0033.html
Reported-by: Tim

Closes https://github.com/curl/curl/pull/1121

Curl_auth_decode_digest_http_message(): copy terminating NUL as later
Curl_override_sspi_http_realm() expects a NUL-terminated string.

Fixes #1180

Mentioned in #1013

Reviewed-by: Peter Wu
Closes #1149
Fixes #1147

Reviewed-by: Nick Zitzmann
Closes #1173

Reviewed-by: Nick Zitzmann
Fixes #1172

The <netinet/tcp.h> is a leftover from the past when TCP socket options
were set in this file. This include causes build issues on AIX 4.3.

Reported-by: Kim Minjoong

Closes #1178

Fixed an old leftover use of the USE_SSLEAY define which would make a
socket get removed from the applications sockets to monitor when the
multi_socket API was used, leading to timeouts.

Bug: #1174

... as the former ones always go stale!

... and regenerated curl.1

... which the help text already implied since we switched to libidn2
from libidn in commit 9c91ec77 back in October 2016.

Reported-by: Christian Weisgerber
Bug: https://curl.haxx.se/mail/lib-2016-12/0110.html

To avoid dereferencing a NULL pointer.

Reported-by: Daniel Romero