Update to rra-c-util 10.5

Update to rra-c-util 10.5

* Assume a working snprintf rather than supplying a replacement.
* Fix detection of reallocarray on NetBSD.
* Check that Kerberos header files were found during configure.
* Use AS_ECHO in all Autoconf macros.
* Always use lib32 or lib64 if it exists, even on Debian.
* Fix rejection of unknown Clang warning flags.
* Disable -Wreserved-identifier for Clang warning builds.

Reformat and restructure Perl code for new perlcritic and perltidy
rules.

heimdal-history now requires the Perl modules Const::Fast and
JSON::MaybeXS instead of Readonly and JSON.