Merge pull request #266 from maciejlew/master

Adds interfaces to managers and functions to change managers
Adds LMSNodeManager and LMSNodeGroupmanager
Adds LMSNetDevManager. Updates LMSNodeManager.
Adds LMSConfigManager
Adds LMSEventManager
Adds LMSMessageManager
Adds LMSHelpdeskManager
Adds LMSFinanceManager
Adds LMSDocumentManager
Renames LMSZipCodemanager to LMSLocationManager. Adds missing methods.
Adds missing methods to LMSNetDevManager
Adds missing methods to LMSNetworkManager
Updates LMS class to use new managers
Formats LMS class