FluidX3D v2.10 (frustrum culling)

Thank you for using FluidX3D! Update v2.10 contains improvents to rasterization performance:

• improved rasterization performance via frustrum culling when only part of the simulation box is visible
• improved switching between centered/free camera mode
• refactored OpenCL rendering library
• unit conversion factors are now automatically printed in console when units.set_m_kg_s(...) is used
• faster startup time for FluidX3D benchmark

Bug fixes:

• miner bug fix in voxelize_mesh(...) kernel
• fixed bug in shading(...)
• replaced slow (in multithreading) std::rand() function with standard C99 LCG
• more robust correction of wrong VRAM capacity reporting on Intel Arc GPUs
• fixed some minor compiler warnings

Have fun with the software!
-- Moritz