check: Apply GStreamer-specific patches

check: Apply GStreamer-specific patches

Reintroduced patches:

 * Make sure that fail_if(1) actually fails
   from commit 9f99d056a263e71a5e6181224829def906cf0226

New patches due to updated libcheck (based on 0.9.14):

 * Checks in m4/check-checks.m4 to cater for new dependencies
 * Conditional compile-time compat POSIX fallbacks for libcheck
 * Avoid relative paths for libcheck header files
 * Make timer_create() usage depend on posix timers, not librt
 * Rely on default AX_PTHREAD behavior to allow HAVE_PTHREAD to be used
   when checking for types and functions (like clock_gettime())
 * Avoid double declaration of clock_gettime() when availabe outside of
   librt by making compat clock_gettime() declaration conditional
 * check 0.9.9 renamed _fail_unless() and 0.9.12 later renamed it again
   to _ck_assert_failed(), so ASSERT_{CRITICAL,WARNING}() now calls this
   function
 * Remove libcheck fallback infrastructure for malloc(), realloc(),
   gettimeofday() and snprintf() since either they appear to be
   available or they introduce even more dependencies.

The result is an embedded check in gstreamer that has been tested by
running check tests in core, -base, -good, -bad, -ugly and rtsp-server
on Linux, OSX and Windows.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=727826