Add WellStateFullyImplicitBlackoil class.

This is intended to be used instead of the WellState class in the fully
implicit blackoil simulator. It contains a WellState to reuse the init()
method and to enable users to call functions requiring a WellState.
This is done with containment and an access member function,
basicWellState(), instead of with inheritance to minimize surprises.
Use WellStateFullyImplicitBlackoil class instead of WellState.
Merge pull request #102 from atgeirr/separate-wellstate

Specialized well state class for the fully implicit blackoil solver.
sim_fibo_ad: get rid of the old parser

currently this requires my 'hacks_for_norne' branch of opm-core...
go back to incrementing the current simulation time first, then calling EclipseWriter::writeSolution()

for this not to trigger an assertation after the last time step, the
changes of OPM/opm-parser#141 are required.
sim_fibo_ad: convert to the new-style wells manager

i.e. it now uses Opm::EclipseState. This change required to re-add the
the epoch concept in some sense, but the loop variables now call it
"episode" which sounds less ethernal IMO.