PHP Deprecated:  substr(): Passing null to parameter #1 ($string) of type string is deprecated in /usr/local/ispconfig/server/plugins-available/bind_plugin.inc.php on line 397

Removed in 2016 via 708b93bd

This preserves the default for non-gentoo systems.

Implemented #4561: SHA256 (ECDSAP256SHA256) Algorithm for DNNSEC and Algorithm selector in DNS zone settings.

This removes duplication of the zone_file_prefix var. It might be nice to make it configurable in a follow up.

Update bind_plugin.inc.php to correct "PHP Parse error:  syntax error, unexpected ':' in /usr/local/ispconfig/server/plugins-available/bind_plugin.inc.php on line 279"

improved crojob

This is a considered as stable stable release. (tested the workflow successfully)
Note: I am not perfect at RegEx I know the RegEx for LOC- and DS-Records is actually not checking. The DS-Regex is definitely valid (tested on regexpal).
Along with my dns-status modification this should not be a problem at all.

Next step is to implement some DNSSEC-Requiring Record Types uon request of some others (will be within this branch before removing the WIP state)