* Elaborates on default values of some curl_easy_setopt() options.
* Reminds the user to cast variadic arguments to curl_easy_setopt() to
  'void *' where curl internally interprets them as such.
* Clarifies the working of the CURLOPT_SEEKFUNCTION option for
  curl_easy_setopt().
* Fixes typo 'forth' → 'fourth'.
* Elaborates on CURL_SOCKET_TIMEOUT.
* Adds some missing periods.
* Notes that the return value of curl_version() must not be passed to
  free().

Always interprets the pointer passed with the CURLOPT_WRITEDATA or
CURLOPT_READDATA options of curl_easy_setopt() as a void pointer in
order to avoid problems in environments where FILE and void pointers
have non-trivial conversion.

* Adds several links to documentation of library functions which were
  missing.
* Marks documentation of deprecated library functions "(deprecated)".
* Removes spurious .html suffixes.

Use Curl_pp_moredata() in Curl_pp_multi_statemach() to check if there is
more data to be received, rather than the socket state, as a task could
hang waiting for more data from the socket itself.

Fixed an incorrect variable reference which was introduced in commit
a1701eea as a result of a copy and paste from SMTP/POP3.

A simple function to test whether the PP is not sending and there are
still more data in its receiver cache. This will be later utilized to:

1) Change Curl_pp_multi_statemach() and Curl_pp_easy_statemach() to
   not test socket state and just call user's statemach_act() function
   when there are more data to process, because otherwise the task would
   just hang, waiting for more data from the socket.

2) Allow PP users to read multiple responses by looping as long as there
   are more data available and current phase is not finished.
   (Currently needed for correct processing of IMAP SELECT responses.)

I just noticed Metalink support wasn't listed as a feature of the tool.

The this_url pointer wasn't being initialized, so if strdup() would return
null when copying the filename in a metalink file, then hilarity would
ensue during the cleanup phase. This change was brought to you by clang,
which noticed this and raised a warning.

Schannel and darwinssl use the certificates built into the
OS to do vert verification instead of bundles. darwinssl
is thread-safe. Corrected typos in the NSS docs.

The attempt to use gai_strerror() or alternative function didn't work as
the 'sock_error' field didn't contain the proper error code. But since
this hasn't been reported and thus isn't really a big deal I decided to
just scrap the whole attempt to output the detailed resolver error and
instead remain with just stating that the resolving of the name failed.

conversion to 'int' from 'long int' may alter its value

follow-up to commit ed7174c6, rename 'wait' to 'block'

It seems older gcc installations (at least) will cause warnings if we
name a variable 'wait'. Now changed to 'block' instead.

Reported by: Jiří Hruška
Bug: http://curl.haxx.se/mail/lib-2013-02/0247.html

Apple made a number of changes to Xcode 4. The SDKs were moved, the entire
Developer folder was moved, and PowerPC support was removed. The script
will now adapt to those changes and should be future-proofed against
additional changes in case Apple moves the Developer folder ever again.
Also, the minimum OS X version compiler option was removed, so that the
framework can be built against the latest SDK but still run in older cats.

Tidied up result variables to be consistent in name, declaration order
and default values.

Fixed a 64-to-32 compiler warning raised when building with
clang and the --with-darwinssl option.

Pointed out by Steve Holme

Due to the reordering of functions in commit 586f5d36 the forward
declaration to state_upgrade_tls() are no longer required.

Repaired all curl/lib/checksrc.pl warnings in the previous four patches

Added WIN32 threading support for PolarSSL entropy if
--enable-threaded-resolver config flag is set and process.h can be found.

Added pthread support for polarssl entropy if --enable-threaded-resolver
config flag is set and pthread.h can be found.

Add non-threaded entropy and ctr_drbg and removed HAVEGE_RANDOM define

Print out human readable error strings for PolarSSL related errors

Since the function takes no argument, the macro shouldn't take one as
some compilers will error out on that.

... since they're not used by the easy interface really, I wanted to
remove the association. Also, I unified the pingpong statemachine driver
into a single function with a 'wait' argument: Curl_pp_statemach.

Remove tailing whitespace introduced in commit 7ed689d2.