Fixes galore, System Settings image, new default delay, and more!

• Bug fixes for instant loading when coming out of several areas when a delay was configured.
• Bug fixes for the disabled state of the feature.
• Set a default value for a delay of 100ms per suggestion from @birdybro (thanks)! (You can now omit the dynamic_wallpaper_delay from the ini if you don't want a custom value.)
• New Feature: If you have a "System Settings.png" (or .jpg), it will display that while in the System Settings area.
• Bug fix for searching the file list in System Settings for image names matching the script names.
• Improved fuzzy name matching for cases with directories; it will now search for a file name without a leading underscore. (This is great for those with the "alternatives" folder if you already have an image file with a game name; it might cover the main game, the folder, and many alts.)
• Likely a few other small bug fixes that I worked on.

(Of special note: Today's release is dedicated to my son who I spent half the day with at the hospital for a not-so-fun procedure. He was diagnosed today with a lifelong condition that he will have to manage. He's tough as nails already...tougher than I am. I love you, little guy.)

Softer file matching, no unnecessary redraw, & code cleanup

Much of the code I wrote has been moved out of video.cpp and into menu.cpp allowing for further things to occur more naturally. This also gets out of most of what was happening in video.cpp most of the time.

The ini variables have been renamed to dynamic_wallpaper and dynamic_wallpaper_delay to match what I was calling it originally. So if you already implemented this, be sure to tweak those values.

I also added softer file matching so you can have naming that'll not require all the additional parentheses/brackets. For example, you can have 1942.png and it'll find that just fine for 1942 (Revision B). It also no longer attempts to redraw the background if the next file name matches the previous one. (Thanks @asturur for the suggestion.)

Dynamic Wallpapers alpha testing binary

This forked binary demonstrates dynamic wallpapers available in the main menu on MiSTer. Please note that this is simply for testing purposes and is not likely to be maintained long-term in any way/shape/form.

To make this work, you need to do the following:

First, I suggest backing up your existing MiSTer executable. Once done, replace it with this test executable.

Wallpapers should be either .png or .jpg files and placed in the standard wallpapers directories. The images should be named exactly as the entries in the MiSTer Main Menu show.

For example, if you were hovering on "Street Fighter II' Champion Edition (World 920513)", you would need an image file in your wallpapers folder, such as "/media/fat/wallpapers/Street Fighter II' Champion Edition (World 920513).png". Please note that this should work for anything in the menu, so for _Arcade, you can create an _Arcade.jpg and it would display when that is selected. Also, characters that are typically illegal in file names are stripped out. For example, if your menu selection is "Neo Geo MVS/AES", you would need an image such as "Neo Geo MVSAES.png"; note the missing "/" from the file name.

Add the following to your MiSTer.ini to enable the feature:
game_wallpapers=1

You can (and probably should) also configure a delay that helps with menu navigation speed:
game_wallpapers_delay=<0-3000> (for example, "game_wallpapers_delay=100")

This value is in milliseconds between 0-3000. You may have to toy around with the values to find exactly what you want, but I found for myself that 100ms will avoid redrawing the wallpaper after the initial movement, but will draw it nearly instantly after stopping movement in the menu. If I choose 500ms, then the initial movement won't redraw the wallpaper, but there is a longer wait after stopping on the menu item that I want. It's all about personal preference.

If you do try this out, please know that I appreciate your time. If you find anything that's just completely out of whack, feel free to let me know.
Thanks!
-soul