Move ExpireParticleIntiializer.
It may be placed under wrong package.
Merge pull request #202 from yhuiyang/upstream-moveExpireParticleInitializer

Move ExpireParticleIntiializer to initializer package.
Merge branch 'GLES2-AnchorCenter' of git://github.com/nicolasgramlich/AndEngine into GLES2-AnchorCenter