Minor fixes and improvements on settings

[123jimin]

• Color settings and enum settings made sure not to be clipped because of insufficient scroll area
• Previously hidden fullscreen setting added to settings page
• Game window position now saved
• Window outside of monitor display region now fixed according to the setting AdjustWindowPositionOnStartup (on by default)
  • It works a little bit annoyingly when the window was maximized before, due to different border size, but otherwise works fine.
  • The annoying behavior is not a regression (same thing happens on master branch of USC)
• Settings renaming and relocations
  • "Display" renamed to "Visual" to reduce confusion between it with systems graphic settings
  • Offset settings moved from "Input" to "Game"
  • Other minor movements
• Out-of-bounds enum settings now shown to be out-of-bound (also related to the next fix)
• Fixes [Bug] Buttons cannot be remapped after removing an unused controller outside of the game. #439: slightly more detailed error messages
• When binding controller buttons, the escape key will cancel the binding. (It's unfortunate that the same can't be done for keyboard key binding screen...)
• Adjusted font baking algorithm so that required texture size for fallback font is reduced (32768 to 8192)
  • Any GPU supporting DirectX 10 should be able to bake the font texture now.
  • Partial baking support: if supported texture size is not big enough, only hiragana/katakana characters are baked.
    • This requires only 1024 x 1024 px texture support; any device supporting OpenGL ES 3.0 should be able to handle this.
• Same for multiplayer chat, but partial baking is not supported (not a big problem as required texture size is still reduced)

[123jimin]

... but I didn't do this as the code will be too complex for a small task of relocating the window.