modify billboardparticlesysytem
Merge branch 'master' of https://github.com/fusijie/FantasyWarrior3D
Merge pull request #99 from zaojiahua/master

modify billboardparticlesysytem
Merge branch 'master' of https://github.com/fusijie/FantasyWarrior3D
fixed a bug when receive message 'SPECIAL_PERSPECTIVE'
1 add critical attack
2  decrease special attack chance