Explain the callback and its arguments better and with more descriptive
text.

Add an XML stream parsing example using Expat. Add missing ignore for
the binary from an unrelated example.

I found a bug which cURL sends cookies to the path not to aim at.
For example:
- cURL sends a request to http://example.fake/hoge/
- server returns cookie which with path=/hoge;
  the point is there is NOT the '/' end of path string.
- cURL sends a request to http://example.fake/hogege/ with the cookie.

The reason for this old "feature" is because that behavior is what is
described in the original netscape cookie spec:
http://curl.haxx.se/rfc/cookie_spec.html

The current cookie spec (RFC6265) clarifies the situation:
http://tools.ietf.org/html/rfc6265#section-5.2.4

This reverts commit 8ec2cb55.

We don't have any code anywhere in libcurl (or the curl tool) that use
wcsdup so there's no such memory use to track. It seems to cause mild
problems with the Borland compiler though that we may avoid by reverting
this change again.

Bug: http://curl.haxx.se/mail/lib-2013-05/0070.html

Reported by: David Strauss
Bug: http://curl.haxx.se/mail/lib-2013-05/0088.html

Bug: http://curl.haxx.se/bug/view.cgi?id=1220
Patch by: John Gardiner Myers

... and de-duplicate the code initializing *passphrase

comparison between signed and unsigned integer expressions

If the mail sent during the transfer contains a terminating <CRLF> then
we should not send the first <CRLF> of the EOB as specified in RFC-5321.

Additionally don't send the <CRLF> if there is "no mail data" as the
DATA command already includes it.

... which was missed in commit: f5c3d953

... which was missed in commit: f5c3d953

Introduced in commit: 51481766

...and removed references to libcurl and test1406.

The code within #ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID wrongly had two
closing braces when it should only have one, so builds without that
define would fail.

Bug: http://curl.haxx.se/mail/lib-2013-05/0000.html

Move the eob counter from the smtp_conn structure to the SMTP structure
as it is associated with a SMTP payload on a per-request basis.