basic tab-based MDI frame window support 'under construction'

[bombasticbob]

basic tab-based MDI frame window support 'under construction'.

• [ ] Able to create an SDI or MDI frame
• [x] scrollable tabs across the top, just under the main menu, with left/right scroll buttons
• [x] ctrl+alt+pgup and ctrl+alt+pgdn hotkeys for left/right scroll
• [ ] optional toolbar(s) located above the tabs (fixed, not dockable)
• [x] button on the tab bar to add a tab (equivalent to 'file new')
• [x] buttons on the tabs to close a tab (equivalent to 'file close')
• [ ] able to 'drag' a tab to change the display order
• [x] support owned (child) windows within a 'WBChildFrame' that are automatically hidden/shown
• [ ] support 'wizard mode' for the frame window (it's not much of a stretch to consider)
• [ ] support 'property dialog' mode for the frame window
• [ ] support 'dialog mode' for the child frames (a new derived type)
• [ ] support multiple rows of tabs instead of just one, up to the limit of sanity

other requirements to be added