Hotkeys and cross tool input fixes

[Dregu]

• Fixed most of the issues with OL and PL inputs clashing and doing stuff in both. OL now ignores keyboard / mouse input when PL is typing / hovering UI
• Also fixed ImGuiIO.wantkeyboard to disable input in the other tool
• Added set_hotkey(fun(chord), KEY chord, HOTKEY_TYPE flags) to hook keys though global windows hotkeys, which should once and for all skip all game input and other UI input
• Added GuiDrawContext:key_picker(string message, KEY_TYPE flags) to capture any key easily
• Added some more input functions and documentation to ImGuiIO