date -u -d@"12345" does not produce an error on *BSD and outputs the
current date in UTC, which is not the expected output from _time2str()
Fix, reorder _time2str() to attempt BSD style date first, which
errors on Linux, so cascade style OS detection works correctly.
Eliminated php dependency with a private function for urlencode using sed. Php had failed on godaddy due to multiple php instances and naturally cron using the one without the necessary -r option. Compared to previous PR the sed code is now POSIX and should work on all environments.
HAProxy requires the certificate chain and key to be concatenated and placed somewhere (can be anywhere). This script expects a single environment variable with the path where the concatenated PEM file should be written