Proper 3D Particle system

Fix the findings collected with 6.1 TP 3D Particle system

Improvements:

• sprite particle support extended (looping, pingpong, different modes)
• alpha improvements (hasTransparency)
• attractor API improvements (support attractors that change (rotation, scale) during runtime)

New features:

• sorting & sorting modes
• mesh shape support for emitters
• shader feature levels - use simpler shaders for simpler particles
• model blend particles (as TP?)