Fixes warnings 78c25c85 added.

IoctlSocket() apparently wants a pointer to a long, passed as a char *
in its third parameter. This bug was introduced already back in commit
c5fdeef4 from October 1 2001!

Bug: http://curl.haxx.se/mail/lib-2015-11/0088.html
Reported-by: Norbert Kett

Reported-by: Mohammad AlSaleh

Commit f3bae6ed added the URL index to the password prompt when using
--next. Unfortunately, because the size_t specifier (%zu) is not
supported by all sprintf() implementations we use the curl_off_t format
specifier instead. The display of an incorrect value arises on platforms
where size_t and curl_off_t are of a different size.

The RTSP code path didn't skip adding the if-modified-since for certain
RTSP code paths, even if CURLOPT_TIMECONDITION was set to
CURL_TIMECOND_NONE.

Also, an unknown non-zero CURLOPT_TIMECONDITION value no longer equals
CURL_TIMECOND_IFMODSINCE.

Bug: http://stackoverflow.com/questions/33903982/curl-timecond-none-doesnt-work-how-to-remove-if-modified-since-header

... and add a generic explanation for them instead. Each example file
should contain its own description these days.

Fixes #534
Closes #537

It would previously be skipped if an existing error was returned, but
would lead to a previous value being left there and later used.
CURLINFO_TOTAL_TIME for example.

Still it avoids that final progress update if we reached DONE as the
result of a callback abort to avoid another callback to be called after
an abort-by-callback.

Reported-by: Lukas Ruzicka

Closes #538

... to also mention the specific options used.

This reverts commit 64e959ff.

Feedback-by: Dan Fandrich
URL: http://curl.haxx.se/mail/lib-2015-11/0062.html

Refer to _HEADERDATA not _WRITEDATA.

Reported-by: Michał Piechowski

smb.c:134:3: warning: conversion to 'short unsigned int' from 'int' may
             alter its value
smb.c:146:42: warning: conversion to 'unsigned int' from 'long long
              unsigned int' may alter its value
smb.c:146:65: warning: conversion to 'unsigned int' from 'long long
              unsigned int' may alter its value

Regression from commit 7a8e861a as highlighted in the msys autobuilds.

pop3-multi.c:96:5: warning: implicit declaration of function 'memset'
imap-multi.c:96:5: warning: implicit declaration of function 'memset'
http2-download.c:226:5: warning: implicit declaration of function 'memset'
http2-upload.c:290:5: warning: implicit declaration of function 'memset'
http2-upload.c:290:5: warning: implicit declaration of function 'memset'

test845 not present in tests/data/Makefile.inc

Moved some ideas from "next major" to just ordinary ideas since we can
always add new things while keeping the old without doing a "next
major".

Add error-checking to 'cd' in a few cases where omitting the checks
might result in an infinite loop.

Closes #535

When an option's help string contains literal single quotes, those
single quotes would be stripped from the option's description in the
completion output (unless the zsh RC_QUOTES option were set while the
completion function was being sourced, which is not the default).  This
patch makes the completion output contain single quotes where the --help
output does.

Closes #532

Closes https://github.com/bagder/curl/pull/533

The push headers are freed after the push callback has been invoked,
meaning this code should only free the headers if the callback was never
invoked and thus the headers weren't freed at that time.

Reported-by: Davey Shafik

Closes #528

... if there are more than one using the same name

As POP3 final and continuation responses both begin with a + character,
and both the finalcode and contcode variables in SASLprotoc are set as
such, we cannot tell the difference between them when we are expecting
an optional continuation from the server such as the following:

+ something else from the server
+OK final response

Disabled these tests until such a time we can tell the responses apart.