Move the update of rs and rv after the phase transitions
The old rs and rv values are used in the phase transitions calculations.
The update of rs and rv to the state is therefore moved after the phase
transitions in order for the code to use the old values.
do not keep oil/gas saturated if privious sg/so is sufficient large
Use the same relative threshold for drs and drv update
The drs_max_rel param is renamed to dr_max_rel and used to restrict both
drs and drv.
Merge pull request #227 from totto82/fix_updateState3

Fixes in updateState