handle comments and empty lines directly in the parser's main loop

note that comment handling is currently a bit too simplistic as stuff
like

FOO
'-- hello' /

won't work. as far as I can see, this is not different from the state
before this patch, though.
don't enter the parsing main loop if the leftover-from-last time keyword does not have any records
Parser::parseState(): remove the 'verbose' debugging facility

This one could only be enable by modifying the source code. If such
debugging output is needed, it should be directly added via std::cout
and removed it before proposing the PR...
Well(Injection|Production)Properties: adapt it to the naming and style conventions of the rest of the module

this patch only changes the conventions which are internal to the
code, i.e., users of these classes do not need to be adapted...
add a "Transmissibility" unit

this is required because Eclipse is inconsistent when specifying
transmissiblities: the only difference between transmissibilities in
metric and field units is that the pressures are in bars instead of
PSI, i.e. the numerator for metric units is still given in centi-Poise
times bbl. This makes it impossible to specify the transmissibilities
in terms of their constituting bits...
add the NNC keyword

this can be used to directly specify transmissibilities for
NNCs. Note that this keyword is quite a mess for everything after
the mandatory items according to the documentation.
add the TRAN[XYZ] keywords

these are required to directly specify the transmissibility of
neighboring connections.
add grid properties for the TRAN[XYZ] keywords
Merge pull request #382 from andlaus/transmissibility_input

Transmissibility input
Merge pull request #339 from andlaus/low_level_improvments

Low level improvments
get rid of the 'strict parsing' concept

this is the 'Joakim-style' variant of the patch, i.e., an exception
will always be thrown if an unknown keyword is encountered.
Merge pull request #347 from andlaus/always_parse_strictly

get rid of the 'strict parsing' concept
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