Changes in initialization, relative permeability and pvtmodels to synch with Mrst and Eclipse

This PR includes the following changes. 

1. The relperm is changed to reflect eclipse and mrst  
2. A function that computes saturation based on surface volume is added to compute initial saturation that 
asserts initial mass conservation. 
3. Cases where the calculated gas resolution factor equals the tabulated gas resolution factor is now judged as saturated. This is important as the gas resolution factor is set to equal for saturated cases in the appleyard process. 
4. The name of the initBlackoilSurfaceVolume that computes surface volumes based on the rs factor is changed to initBlackoilStateFromDeckUsingRS to avoid duplication with the original initBlackoilSurfaceVolume that computes the surface volumes based on saturation. 
5. Functions that takes as input whether the fluid is saturated or not is added in the pvt files. This facilitates the simulator to decide the conditions for whether the fluid is saturated or not. 

With these changes SPE1 and a simplified SPE9 without PC and with only two wells matches Mrst and Eclipse reasonably well.