增加线的绘制，修改相机使观察时Z轴向上！

Signed-off-by: yhexie <yhlx125@163.com>
增加模型

Signed-off-by: yhexie <yhlx125@163.com>
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Merge branch 'master' of https://github.com/yhexie/RGeos.SlimScene

Conflicts:
	RGeos.AppScene/MainFrm.cs