Fully implicit incompressible oil-water simulator

This PR  introduces the fully implicit incompressible oil-water simulator, include follow features.
 - Incompressible properties based on AD, which will is used not only just here, but also for the  upcoming fully implicit incompressible oil-water-polymer simulator.
- IncompPropsAdBasic.cpp is used to create a fast and simple prototype.
 - sim_fi2p_incomp_ad is the simulator, can handle BHP and SURFACE_RATE type well controls, the same with sim_fibo_ad.
 -  for .gitignore file, this my local setting, usually I build the code in `build/` directory, to be honest I don't want to push this file to the base, but the problem is that I don't how to not include it ...

Any comment is appreciated!