Merge commit 'ebef9f5a56d7df91e010a177a80cfc8dbe394305'

* commit 'ebef9f5a56d7df91e010a177a80cfc8dbe394305':
  time: Use clock_gettime if the monotonic clock is available

Conflicts:
	configure

The change to av_gettime() isnt merged, a patch will be posted to the mailing list
that would do the switch

Merged-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -4655,7 +4655,7 @@ check_func  ${malloc_prefix}memalign            && enable memalign
 check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign
 
 check_func  access
-check_func  clock_gettime || { check_func clock_gettime -lrt && add_extralibs -lrt; }
+check_func_headers time.h clock_gettime || { check_func_headers time.h clock_gettime -lrt && add_extralibs -lrt; }
 check_func  fcntl
 check_func  fork
 check_func  gethrtime