EclipseWriter: Don't mingle multiple operations using arguments

This means that EclipseKeyword now never processes the data it
gets. Instead the data must be explicitly preprocessed by the calling
site using the new auxiliary functions "convertUnit()",
"extractFromStriped()", etc. This approach needs a few additional
temporary copies of the data, but given the facts that readability of
this code is much better using this approach, and that EclipseWriter
is neither a performance- nor a memory critical codepath, I don't care
too much about those temporary arrays...
EclipseWriter: add method variants taking the new instead of the old parser
SimulatorTimer: allow it to be limited to a sub-range of all report steps

here, "report step" is called "episode" because it's shorter than
"report step" and it's less "eternal" than "epoch"...
endpoint scaling: hack around some unimplemented functionality in SatFuncSimple

at least i *think* it's unimplemented...
fix densities for new parser in BlackoilPvtProperties

that is one of the more subtle differences between the old and the
new parsers. now, valgrind does not seem to complain anymore, so everything
should be All Right (TM) ;)