Release v0.5.0

new features:

• OnCloned/OnKey/OnScene
• support List
• support stageMonitor
• support switch -f (fullscreen)
• Game.Initialize
• Value.Int
• Round
• abortThread
• event debug
• tutorial/02-Dragon
• tutorial/03-Gobang

changes:

• remove sprite.Sink events (old code style)
• mv tutorial 02-Weather => 01-Weather: remove old style code
• spx README