libroot: remove delete_driver_settings

It is not present in BeOS R5 and it just call unload_driver_settings.

Replace delete_driver_settings usages with unload_driver_settings.
Keep the symbol on x86 for binary compatibility.

Change-Id: I1382710e3a4cb5c65d1249ea0e5880891e6800e4
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3485
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

launch_daemon: Started working on condition parsing.

* Moved related test code from DriverSettingsMessageAdapterTest to the
SettingsParser class.
* Added SettingsParserTest class -- most tests already succeed, but not
all; support for the flattened "not" is not working yet.

DriverSettingsMessageAdapter: added "wildcard" support.

* You can now add arbitrarily named fields to the message as well,
without having them all specified in the template.
* Also added a missing converter method that is called when there
are no values to add, and implemented all methods in the base
class, so that you only have to implement the methods you actually
need.

Fix unittests build.

DriverSettingsMessageAdapter: fixed converter signature.

* The ConvertFromDriverSettings() method missed the current value
index.
* Completed unit tests, and enabled them all.

DriverSettingsMessageAdapter: fixed various issues.

* _AddParameter() would ignore all BMessage::Add*() errors.
* _ConvertFromDriverParameter() would ignore most intermediate error,
but would fail badly over some incorrect settings file.
* Also, it checked for the parent value for each parameter, which
doesn't make any sense, but would add as often as there are
parameters -- which also may be none, in which case the value
got ignored.

launch_daemon: Started working on condition parsing.

* Moved related test code from DriverSettingsMessageAdapterTest to the
SettingsParser class.
* Added SettingsParserTest class -- most tests already succeed, but not
all; support for the flattened "not" is not working yet.

DriverSettingsMessageAdapter: added "wildcard" support.

* You can now add arbitrarily named fields to the message as well,
without having them all specified in the template.
* Also added a missing converter method that is called when there
are no values to add, and implemented all methods in the base
class, so that you only have to implement the methods you actually
need.

Fix unittests build.

DriverSettingsMessageAdapter: fixed converter signature.

* The ConvertFromDriverSettings() method missed the current value
index.
* Completed unit tests, and enabled them all.

DriverSettingsMessageAdapter: fixed various issues.

* _AddParameter() would ignore all BMessage::Add*() errors.
* _ConvertFromDriverParameter() would ignore most intermediate error,
but would fail badly over some incorrect settings file.
* Also, it checked for the parent value for each parameter, which
doesn't make any sense, but would add as often as there are
parameters -- which also may be none, in which case the value
got ignored.