[v9_11] fix dyndb issues; isc_errno_toresult() 4445. [cleanup] isc_errno_toresult() can now be used to call the formerly private function isc__errno2result(). [RT #43050] 4444. [bug] Fixed some issues related to dyndb: A bug caused braces to be omitted when passing configuration text from named.conf to a dyndb driver, and there was a use-after-free in the sample dyndb driver. [RT #43050] Patch for dyndb driver submitted by Petr Spacek at Red Hat. (cherry picked from commit 3390d74e33385337631b19e68760025e0ca5d6ec)

[master] merge dyndb 4224. [func] Added support for "dyndb", a new interface for loading zone data from an external database, developed by Red Hat for the FreeIPA project. DynDB drivers fully implement the BIND database API, and are capable of significantly better performance and functionality than DLZ drivers, while taking advantage of advanced database features not available in BIND such as multi-master replication. Thanks to Adam Tkac and Petr Spacek of Red Hat. [RT #35271]