Added a new Window for user management. This window is displayed when the
menu item is selected.
Changed window manager to be a stack wrapper instead of a list.
Assuming that all windows will be fullscreen and will stack on top of
one another.
Removed some unecessary member variables.
Created a DatabaseWindow to handle the database options described in
the project reports. Currently Raw Query option will let the user enter
a query and then click execute, but no actual database work is done.
Now application connects to the database using the settings in
db_settings.xml.
Raw query functionality now works!!