libtest: fixed duplicated line in Makefile

Bug: https://github.com/bagder/curl/pull/105
test1013.pl: GSS-Negotiate doesn't exist as a feature anymore
symbols: CURL_VERSION_GSSNEGOTIATE is deprecated
SSPI Negotiate: Fix 3 memory leaks

Curl_base64_decode allocates the output string by itself and two other
strings were not freed either.
base64: added Curl_base64url_encode()

This is now used by the http2 code. It has two different symbols at the
end of the base64 table to make the output "url safe".

Bug: https://github.com/tatsuhiro-t/nghttp2/issues/62
Curl_base64url_encode: unit-tested in 1302
c-ares: fix build without IPv6 support

Bug: http://curl.haxx.se/mail/lib-2014-07/0337.html
Reported-by: Spork Schivago
getpart.pm: Fix a comment typo
runtests.pl: Don't expect $TESTDIR/DISABLED to exist

If a non-standard $TESTDIR is used the file may not be necessary.

Previously a "missing" file resulted in the warning:
readline() on closed filehandle D at ./runtests.pl line 4940.
runtests.pl: Remove filteroff() which hasn't been used since 2001
tests: Fix a couple of incomplete response lines
curl.h: bring back CURLE_OBSOLETE16

Removing defines, even obsolete ones that haven't been used for a very
long time, still break a lot of applications.

Bug: https://github.com/bagder/curl/pull/106
nss: do not check the version of NSS at run time

The minimal required version of NSS is 3.14.x so it does not make sense
to check for NSS 3.12.0+ at run time.