Reported by: Santhana Todatry

Bug #75 updated with additional info, still remains for builds with
other backends.

Mention the CURL_SOCKET_TIMEOUT argument in step 6 of the typical
application.

Added function macros to make path converting easier.
Added CROSSPREFIX to all compile tools.

Documented that --include will be ignored if both --metalink
and --include are specified.
Also documented that a Metalink file in the local file system
cannot be used if FILE protocol is disabled.

Bug: http://curl.haxx.se/mail/lib-2012-06/0302.html
Reported by: Nagai H

Version number is removed in order to make this info consistent with
how we do it with other MS and Linux system libraries for which we don't
provide this info.

Identifier changed from 'WinSSPI' to 'schannel' given that this is the
actual provider of the SSL/TLS support. libcurl can still be built with
SSPI and without SCHANNEL support.

The r7b had some bugs, and shouldnt be used.

- For all *FUNCTION options, they now all show the complete prototype in
  the description. Previously some of them would just refer to a
  typedef'ed function pointer in the curl.h header.

- I made the phrasing of that "Pass a pointer to a function that matches
  the following prototype" the same for all *FUNCTION option descriptions.

- I removed some uses of 'should'. I think I sometimes over-use this
  word as in many places I actually mean MUST or otherwise more specific
  and not-so-optional synonyms.

Added new sections 11. IMAP and 12. LDAP to document adding SASL based
authentication.

Renumbered current sections 11 to 17 as 13 to 19.

Additionally added 19.10 Add CURLOPT_MAIL_CLIENT option.

Additionally corrected another RFC link that I missed yesterday.