The water/gas pressures are only calculated if woc and goc lies within
the reservoar
The water/gas pressure is set to -inf when woc and goc is above or below
the reservoar.
Fixes issues pointed out in the PR comments
FindQuadmath: add -fext-numeric-literals if the compiler supports it

this is required for GCC >= 4.8 to support the 'Q' suffix for floating
point literals (which are used in the quadmath.h header)

In order to prevent compilers which eat the flag but do not support it
from complaining constantly, it is tested for with "-Werror" enabled...
CornerpointChopper::writeGrdecl(): Write fewer items per line

This is in preparation of increasing the vector output precision to
reduce the impact of rounding errors in subsequent upscaling.  The
change impacts floating-point vectors only.

Background: The ECL simulator stipulates an upper bound on the
number of characters in a record (i.e., one line) and while we don't
have such limits, there's no reason to emit lines that can't be
input by other tools.
CornerpointChopper::writeGrdecl(): Increase vector precision

This commit increases the precision of the (floating-point) vector
output (e.g., permeabilities) from method writeGrdecl().  This
reduces the impact of rounding errors when the sub-set sample is
output to disk for subsequent processing (e.g., property upscaling).
Merge pull request #632 from bska/cpchop-precision

Increase precision from CornerpointChopper::writeGrdecl
Merge pull request #630 from totto82/fix_init_spe9

The water/gas press. are calculated only if woc/goc is within the reservoar
Merge pull request #631 from andlaus/add_-fext-numeric-literals

FindQuadmath: add -fext-numeric-literals if the compiler supports it