This utility method serves as alternative for all previous custom solutions to prevent empty values from being persisted to INI files.
Since the IniWriter now handles NULL correctly, we're able to refrain from using array_filter for this purpose which was the actual cause for the referenced bug.
fixes#13357
Zend returns values from subforms grouped by their names and we have several places where we manually extract them. ConfigForm::getValues() does this automatically now.
Simplifies saving INI files. Icinga\File\Ini\IniWriter does already require an
instance of Icinga\Application\Config so it's obvious to give "Config" the
task to initialize the writer.. We do also have a central place to handle
creating missing ancestor directories now.
refs #8219
We do not want to override Zend_Form::setConfig() so this renaming is
required. set*Ini*Config() because ConfigForm::save() utilizes an ini-writer
to persist the configuration to disk.
refs #5525