bug introduced by 18691642.

Closes #493

introduced in c6aedf68. It needs to be CURLM_STATE_LAST big since it
must hande the range 0 .. CURLM_STATE_MSGSENT (18) and CURLM_STATE_LAST
is 19 right now.

Reported-by: Dan Fandrich
Bug: http://curl.haxx.se/mail/lib-2015-10/0069.html

... and assign it from the set.fread_func_set pointer in the
Curl_init_CONNECT function. This A) avoids that we have code that
assigns fields in the 'set' struct (which we always knew was bad) and
more importantly B) it makes it impossibly to accidentally leave the
wrong value for when the handle is re-used etc.

Introducing a state-init functionality in multi.c, so that we can set a
specific function to get called when we enter a state. The
Curl_init_CONNECT is thus called when switching to the CONNECT state.

Bug: https://github.com/bagder/curl/issues/346

Closes #346

... and allow it to get set by a caller easier.

Reported-by: Rainer Jung
Bug: http://curl.haxx.se/mail/lib-2015-10/0035.html

sk_X509_pop will decrease the size of the stack which means that the loop would
end after having added only half of the certificates.

Also make sure that the X509 certificate is freed in case
SSL_CTX_add_extra_chain_cert fails.

It makes it a clearer message for developers reaching that point without
the necessary support.

Thanks-by: Jay Satiro

Closes #78

follow-up from 6f8ecea0

... as in the polarssl TLS backend for example it uses memory functions.

If the underlying recv called by http2_recv returns -1 then that is the
value http2_recv returns to the caller.

Closes #479

... since some compilers don't have it and instead use other types, such
as __int64.

Reported by: gkinseyhpw
Closes #478

Follow up to 613e5022.

'make V=1' will make the build verbose like before

- If a CURLINFO option is unknown return CURLE_UNKNOWN_OPTION.

Prior to this change CURLE_BAD_FUNCTION_ARGUMENT was returned on
unknown. That return value is contradicted by the CURLINFO option
documentation which specifies a return of CURLE_UNKNOWN_OPTION on
unknown.

Closes https://github.com/bagder/curl/pull/471

Closes https://github.com/bagder/curl/pull/469

Closes #466

Because the 'not' operator has a very low precedence and as a result the
entire statement was erroneously negated and could never be true.

- Change algorithm init to happen after OpenSSL config load.

Additional algorithms may be available due to the user's config so we
initialize the algorithms after the user's config is loaded.

Bug: https://github.com/bagder/curl/issues/447
Reported-by: Denis Feklushkin

Closes https://github.com/bagder/curl/pull/459

For a single-stream download from localhost, we managed to increase
transfer speed from 1.6MB/sec to around 400MB/sec, mostly because of
this single fix.

... only call it when there is data arriving for another handle than the
one that is currently driving it.

Improves single-stream download performance quite a lot.

Thanks-to: Tatsuhiro Tsujikawa
Bug: http://curl.haxx.se/mail/lib-2015-09/0097.html

... as otherwise a really fast pipe can "lock" one transfer for some
protocols, like with HTTP/2.

Closes #439

... don't try to increase the supposed file size on newlines if we don't
know what file size it is!

Patch-by: lzsiga

Closes #457

... for CURL_CHECK_OPTION_RT

Closes #456