CURLOPT_CONNECT_ONLY.3: Fixed incomplete protocol list

Added missing IMAP to the protocol list.
CURLOPT_GSSAPI_DELEGATION.3: Use GSS-API rather than GSSAPI

As implementations are refereed to GSS-API libraries as per the RFC and
GSSAPI typically refers to an authentication mechanism.
CURLOPT_CONNECT_ONLY.3: Removed "This option is implemented for..." text

As this is covered by the PROTOCOLS section and saves having to update
two parts of the document with the same information in future.
opts: Use common wording for user/password option names
ftplistparser: We prefer 'CURLcode result'
openssl: Use 'CURLcode result'

...and some minor code style changes.
openssl: Use 'CURLcode result'

More standardisation of CURLcode usage and coding style.
resume: consider a resume from [content-length] to be OK

Basically since servers often then don't respond well to this and
instead send the full contents and then libcurl would instead error out
with the assumption that the server doesn't support resume. As the data
is then already transfered, this is now considered fine.

Test case 1434 added to verify this. Test case 1042 slightly modified.

Reported-by: hugo
Bug: http://curl.haxx.se/bug/view.cgi?id=1443
openssl: Use 'CURLcode result'

More CURLcode fixes.
sasl: Fixed Kerberos V5 inclusion when CURL_DISABLE_CRYPTO_AUTH is used

Typically the USE_WINDOWS_SSPI definition would not be used when the
CURL_DISABLE_CRYPTO_AUTH define is, however, it is still a valid build
configuration and, as such, the SASL Kerberos V5 (GSSAPI) authentication
data structures and functions would incorrectly be used when they
shouldn't be.

Introduced a new USE_KRB5 definition that takes into account the use of
CURL_DISABLE_CRYPTO_AUTH like USE_SPNEGO and USE_NTLM do.
CURL_VERSION_KERBEROS4: Mark as deprecated

Support for Kerberos V4 was removed in v7.33.0.
docs: Added mention of Kerberos for CURL_VERSION_SSPI

As this has been present for SOCKSv5 proxy since v7.19.4 and for IMAP,
POP3 and SMTP authentication since v7.38.0.
RELEASE-NOTES: Synced with e7da67f5d3
RELEASE-NOTES: removed obsolete entry; fixed entry.
CURLOPT_MAXCONNECTS.3: Reworked the description to be less confusing

...and corrected a related typo in curl_easy_setopt.3.
opts: Use common wording for TLS user/password option names

...and revised the proxy wording a little as well.
opts: Use common wording for MAIL related names
CURLOPT_SASL_IR.3: Added supported mechanism information

...and removed duplication of what protocols are supported from the
description text.
CURLOPT_XOAUTH2_BEARER.3: Corrected the OAuth version number
build-openssl.bat: Fix x64 release build

Prior to this change if x64 release was specified a failed attempt was
made to build x86 release instead.