write out the reservoir state to the eclipse binary format

most code was shamelessly ripped from opm-core's EclipseGridParser,
but there are some additions (e.g. grids specified using the D[XYZ]V
Eclipse keywords can be used).

The code is located inside the new class "BlackoilEclipseOutputWriter"
(should probably renamed) and hooked up in
SimulatorFullyImplicitBlackoil and sim_fibo_ad.cc.

Also be aware that, to make this code work properly, the newest master
version of ERT is required (i.e. one which includes commit
5e4e9661720). In this context, I would like to thank Joakim Hove for
his support!
write out water injection and oil production rates

Currently, it still writes out whatever conservation quantity which is
used by the solver (which is probably the mass of the oil/gas
mixture). TODO: convert these solver rates to "pure oil volume without
gas at the surface" and to "gas volume at the surface" rates.

thanks again to Joakim Hove for the pointers where to start kicking!
add some rates to the summary output, correct values

it turns out that the values within the WellState are surface volumes,
so they can be used directly once converted to daily rates...
add missing include directives
use bar instead of Pascal as the unit for the pressure field

Eclipse seems to write bars...
Use EclipseWriter from opm-core instead of old impl

Note: The interface here requires opm/opm-core#424.
Remove old Eclipse writer (which is now in opm-core)
Remove redundant read of outputDir

The writer reads this from the params itself.