test815/816: Use authentication for both URLs

The improved connection reuse logic would otherwise create a new
connection for each one, which isn't supported by the test
server, nor expected by the test.
test1397: Fixed compilation with some SSL backends

The test is only valid when one of four SSL backends is in use,
and must otherwise return success.
hostcheck: added a system include to define struct in_addr
winbuild: added warnless.c to fix build
smtp: Fixed login denied when server doesn't support AUTH capability

Specifying user credentials when the SMTP server doesn't support
authentication would cause curl to display "No known authentication
mechanisms supported!" and return CURLE_LOGIN_DENIED.

Reported-by: Tom Sparrow
Bug: http://curl.haxx.se/mail/lib-2014-03/0173.html
ftpserver.pl: Introduced common method for getting a test's reply data
ftpserver.pl: Updated argument code in STATUS_imap() to be more meaningful
ftpserver.pl: Fixed syntax error from commit 3a29ee41
ftpserver.pl: Updated email based get reply data code to use new method
ftpserver.pl: Added fallback to <data> support when using multiple URLs

Added support for falling back to <data> when <data1>, <data2>, etc...
don't exist in the <reply> section of a unit test.
lib1513: fix callback proto to silence warning
ftpserver.pl: Corrected some indentation in senddata()
ftpserver.pl: Reworked some variable names to be more meaningful
ftpserver.pl: Removed some unused variables
imap-append.c: Fixed compilation errors on some platforms

In the initializer for len, there is no prototype for "strlen".
In this statement, there is no prototype for "memcpy".
tests: Added "SASL" authentication keyword
tests: Added "Clear Text" authentication keyword
tests: Replaced email authentication keywords with SASL based keywords

As the email protocols implement SASL authentication rather than IMAP,
POP3 and SMTP specific authentication, updated the authentication
keywords to reflect this.
tests: Corrected "APOP" authentication keyword
tests: Added email unit tests to verify login credential connection re-use