Integrate doxygen with CMake
Add git describe version to CMake
Setup initial main window
Create initial menu and toolbar
Cleans up icons used for menu and main window
Add initial multi-document functionality
Add more multi-document functionality
Add object names to toolbars

When the window is closed, the window state is preserved, and the
object names for all toolbars must be set in order for toolbar
state preservation.
Add remembering of the last-used budget file dir
Add recent-file support to menu
Moves MainWindow definitions to separate files.

Methods that are slots associated with menu/toolbar actions are defined
in MainWindow_actions.cpp. Methods that create or update menus are
defined in MainWindow_menus.cpp. All other methods are defined in
MainWindow.cpp.
Use constants for settings keys
Add save and save-as actions to MainWindow
Remove file name changed signal from Session.

Setting the window title on the Session widget will cause it to be
displayed as the sub-window title. Thus, there is no need for a separate
signal.
Connect remaining menu actions to session
Add status message signal to Session
Add progress indicator to status bar
Add undo/redo availability signals
Merge branch 'ui-module' into qt-rewrite