add a PERFORMANCE_PROBE parser keyword

this contains all performance monitoring keywords like TCPU or PERFORMA
REGION_PROBE: add more user defined keywords

these are not really documented, but they are used by the file
./INCLUDE/SUMMARY/extra.inc of the Norne deck. I don't know why this
did not bite anyone so far, probably people just commented out the
INCLUDE statement of this file...
remove some keywords which are already covered by *_PROBE
remove all trailing spaces from the JSON keyword definitions and make sure that they end with a new line

this makes it easier to create a patch for the respective file using a
python scripts...
JSON keyword definitions: add a "sections" item

this which specifies the allowed sections of the keyword. (surprise!)
ParserKeyword: add the glue code so that it knows its sections

also tighten the checkSectionTopology() test of Opm::Section.

TODO: warn about unknown keywords in the deck. this should probably
done in the EclipseState...
warn if unknown keywords are in the deck

also, move the deck-grooming checks to a separate static method,
EclipseState::checkDeck().
add unit test for EclipseState's checkDeck() method