Rewrite menu from scratch to support mobile sized screens and keyboard controls

[Giwayume]

I removed ddsmoothmenu and wrote a custom menu that tries its best to make sure that each menu dropdown stays on screen at all times.

• config-menu.js has changed to a JSON definition that is easier to read and modify.
• Menu dropdowns will open to the left if run out of space on the right. They might overlap if the screen is small enough.
• Menu keyboard controls have been implemented based on WAI ARIA web standards. https://www.w3.org/TR/wai-aria-practices/examples/menubar/menubar-1/menubar-1.html
• Please test to make sure everything is working as expected. I've covered all the use cases I'm aware of, but could have missed something.

[Giwayume]

#167

[Giwayume]

Hold up, need to get the translations working again.

[Giwayume]

Translations should be good now.

[viliusle]

I like it, you can control it using keyboard, it is nice. Also few issues:

• It does not work on IE11. I was supporting IE11 yesterday, but today - not sure if it is worth. It is time to forget this browser.
• it is very hard to find and focus menu using keyboard only - FIXED.

Did you use any library for src/js/core/gui/gui-menu.js? If yes, let me know, i would add link for documentation.

[Giwayume]

I was supporting IE11 yesterday, but today - not sure if it is worth. It is time to forget this browser.

I agree. Even Microsoft Edge has moved to using Chromium as its rendering engine.

Did you use any library for src/js/core/gui/gui-menu.js?

No, I wrote the entire thing.