Replace eval with constant in getConfInst

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Use self:: instead of AuthService:: in AuthService

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Add abstract functions getUsersCountFromConf, userExistsInConf,
listUsersFromConf in AbstractConfDriver

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Implement functions getUsersCountFromConf, userExistsInConf,
listUsersFromConf in sqlConfDriver

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Implement functions getUsersCountFromConf, userExistsInConf,
listUsersFromConf in serialConfDriver

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Add empty functions getUsersCountFromConf, userExistsInConf,
listUsersFromConf in BootConfLoader.

(~30 empty functions in BootConfLoader)

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Add supportsUsersPaginationInConf const

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Deprecate authCountUsers, introduce getUsersCountFromAuth and getUsersCountFromConf in AuthService

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Introduce userExistsInConf in AuthService

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Introduce listUsersFromConf in AuthService

Please reread/test this one carefully.

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>