Update phase condition vector from primary variables.

This is necessary as an interim measure, since the phase condition vectors are
still used in property calculations.
Added test to ensure active gas phase.
Merge pull request #169 from atgeirr/update-condition

Update phase condition vector from primary variables.

This resolves #168.
Merge remote-tracking branch 'upstream/master' into New_BLACKOIL_SIMULATOR
Finishing changing. Testing Later