fix the unit for transmissibility when using the metric unit system

I don't know why exactly this happend, but anyway thanks to [at] bska
for catching it...
Merge pull request #383 from andlaus/fix_metric_transmissibility_unit

fix the unit for transmissibility when using the metric unit system
make the build fail if a JSON keyword definition file could not be parsed
Merge pull request #386 from andlaus/abort_build_on_invalid_JSON

make the build fail if a JSON keyword definition file could not be parsed
Changes in the log class:

 1. Moved to from eclipse/Parser -> eclipse/Log
 2. Renamed ParserLog -> OpmLog
Added BUILD_TESTING() guard
Removed stale comments - problem has been fixed.
Merge pull request #385 from joakim-hove/move-log

Move and rename ParserLog
add default values required to make it possible to terminate keywords early

for many of them the RM says "default is undefined" but that I've come
to the conclusion that this doesn't mean that no default could be
applied, but that the simulator is allowed to screw up if the values
of them are accessed. (Note that in this sense this change is no
change from the current situation, but makes the screw-up more
explicit.)

In particular, note the GRIDUNIT keyword which had some serious JSON
syntax errors in it but so far the unit tests worked anyway for some
reason...
make items which do not have a default un-defaultable

this was a much more common problem than it seemed initially...
make the parsing stage pass even if non-defaultable items have been defaulted

... but throw later when trying to access the data of the item in
question.

Note that this was demanded by [at] joakim-hove and that I do not want
to be held responsible for any issues which are caused by this
approach. (read: please direct your barks to Joakim if you fell on
your nose because of this...)
Revert "add default values required to make it possible to terminate keywords early"

This is not necessary anymore with approach of the previous commit...
Merge pull request #355 from andlaus/no_default_default

Remove "default" default values
Added EQUALREG json configuration
Added maskedSet() and initMask() GridProperties<T>
Added const to GridProperty::containsNan()
Added GridProperty::getDimensionString()
Added method GridProperties::getInitializedKeyword()

The getKeyword() method will autocreate and initialize a keyword if you
ask for one which is supported, but has not yet been accessed. The new
getInitializedkeyword() method will raise an exception if the keyword
has not already been initialized.
Added support for EQUALREG in EclipseState
Added test for EQUAL.