DP: Reduce Data Provider log level noise Certain operations are not supported with certain providers causing informational Data Provider log messages to be logged as errors or failures. This patch lowers the log level to reduce overall log noise and ensure only critical log messages are logged when a low debug_level value is used. Resolves: https://pagure.io/SSSD/sssd/issue/3287 https://pagure.io/SSSD/sssd/issue/3278 Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com> Reviewed-by: Pavel Březina <pbrezina@redhat.com>

DP: Initialize D-Bus as soon as possible Resolves: https://fedorahosted.org/sssd/ticket/3111 Reviewed-by: Petr Cech <pcech@redhat.com>

DP: Introduce new interface for backend Terminology: * Backend: Implemenation of domain * Data Provider: interface between backend and responders * Module: ldap/ipa/ad/... dlopened library that implements dp interface * Target: id/autofs/sudo/... functionality of module Benefits over current code: * data provider is a black box completely separated from backend * method handlers are just simple tevent requests on backend side * no need of spy on be_client * simplified and error proof adding of new responders * simplified adding of new methods * reply to D-Bus message is completely handled by DP code * each target can have several methods defined * properties can be added on objects * each method can have output parameters * modules now support constructor * improved debugging * clear memory hierarchy * ability to chain requests * type safe private data Reviewed-by: Sumit Bose <sbose@redhat.com> Reviewed-by: Jakub Hrozek <jhrozek@redhat.com> Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>