Merge branch '3.3-maint'

Merge branch '3.3-maint'

* 3.3-maint:
  Run test for undefined behaviour with Travis
  Undefined: avoid shift warning in manifest
  Undefined: avoid shift warning in murmurhash
  Undefined: avoid null warning in tmp_unlink
  Include feature_macros earlier in configure.ac
  Document the different cache statistics counters
  Use correct statistics counter for -optf/--options-file failure
  Update NEWS
  Include names of include files in the hash again