Update atf and atf-libs to 0.17:

* Added the atf_utils_cat_file, atf_utils_compare_file,
  atf_utils_copy_file, atf_utils_create_file, atf_utils_file_exists,
  atf_utils_fork, atf_utils_grep_file, atf_utils_grep_string,
  atf_utils_readline, atf_utils_redirect and atf_utils_wait utility
  functions to atf-c-api.  Documented the already-public
  atf_utils_free_charpp function.

* Added the cat_file, compare_file, copy_file, create_file, file_exists,
  fork, grep_collection, grep_file, grep_string, redirect and wait
  functions to the atf::utils namespace of atf-c++-api.  These are
  wrappers around the same functions added to the atf-c-api library.

* Added the ATF_CHECK_MATCH, ATF_CHECK_MATCH_MSG, ATF_REQUIRE_MATCH and
  ATF_REQUIRE_MATCH_MSG macros to atf-c to simplify the validation of a
  string against a regular expression.

* Miscellaneous fixes for manpage typos and compilation problems with
  clang.

* Added caching of the results of those configure tests that rely on
  executing a test program.  This should help crossbuild systems by
  providing a mechanism to pre-specify what the results should be.

* PR bin/45690: Make atf-report convert any non-printable characters to
  a plain-text representation (matching their corresponding hexadecimal
  entities) in XML output files.  This is to prevent the output of test
  cases from breaking xsltproc later.
Note update of atf and atf-libs to 0.17.
Update to 1.7.1. From the changelog:

  * Fix autoconf issues...
Updated security/knc to 1.7.1