Move all libao operation into interface.cpp
This should have the result of removing all AV and GUI code from apple2e.cpp
OS code remaining in apple2e.cpp should basically be only file I/O, console I/O, and chrono.
Catch ALTCHAR but do nothing about it
Catch VID80 (80VID)
Add aux pages to interface.cpp
Plumb aux pages through apple2e.cpp display_write functions
Implement 80-column text shader using aux page
On cold-start, force Button0/OpenApple on for a short period
This is how cold-start (disk boot) is differentiated from plain RESET
Add padding widget that pads another widget on all sides
Add drag-and-drop functionality to widgets and manage through GLFW
Honor current time through all widget methods
Fix character encoding in text_widget (especially for ' ')
Add floppy_icon widget that manages drag-and-drop and drive motor (activity) light
Later move to vector graphic or bitmap
Add floppy eject and insert notification from APPLE2Einterface
Add activity notification through APPLE2Einterface
Optimize with -O2
Mouse/Trackpad drag across the screen emulates paddles
Click on the screen emulates button 0
Ignore reads from C020 (tape out)
Add BRA instruction for 65C02 (maybe not necessary)
Disable audio in FAST mode
Throttle a little better when audio is enabled - stopped stutter
Move to GL 3.2
Draw a quad with shaders depending on the mode in that part of the screen
HIRES shader reads from hires texture
TEXTPORT shader reads from textpor texture and indirects through a font
to get pixel values
MIXED now supported
Still to do: BLINK text, INVERSE text, LORES, gang up HGR memory updates
Why doesn't cursor flash the checkerboard?
