Fix the buggy Memo editor

Fix the buggy Code editor (memo with syntax highligh).

  1. Memo editor is extremely buggy and can corrupt text. Try to select some text and press Ctrl+C. And hold Ctrl+C. At first selected text will start to flicker, and at some point it might even disappear.
    If you'll try Ctrl+Z you'll only make it worse.

  2. Autocomplete may work. Or may not.

  3. hints may be shown. Or may not. Even on Ctrl+Shift+Space.

There's really much things to improve.

Please report bugs via support. These are not feature requests.

This feature will not be implemented.