advance the SettingConfiger

[Sharlottes]

SettingConfiger will...

• have EventEmitter, for detecting setting changes without any cost, or any dependents.
• store various of types. not only boolean but also float, int... which Core.setting can store.
• Because of the above feature, the consumers who want to configure will resolve their own UI. but that's DRY, so SettingConfiger's subclass will describe which is shown to control the config value.
• The current way to access the SettingConfiger is across classes like ToolManager or OverDrawManager. because SettingConfiger should act like Core.setting but more fast and cheaper, this should be singleton.

These changes will...

• Clean up Setting and ToolWindow codes.
• You can use or listen to setting configuring anywhere, anytime through a pre-supplied UI or interface.