change the parsing of raw keywords

This makes it possible to specify the size of tables without caring
about the appropriate RUNSPEC keyword. E.g. SWOF may now have an
arbitrary number of records while it previously used exactly the
number specified by TABDIMS. (which confused the heck out of me once
I've added a record for testing purposes.) The checkDeck() is now
responsible about warning the user about unknown keywords. (it be
amended in that regard.)

Also, empty records are now added to the keyword even if they happen to be
the last record of the keyword. (before, they were silently eaten.)
get rid of the 'strict parsing' concept

the 'parsing' stage is now always as relaxed as possible. if you want
to verify (or some aspects of) the validity of a deck, use
EclipseState::checkDeck()!
eat keywords containing lowercase letters

The Norne deck actually exhibits this atrocity in form of the
'fluxnum' keyword in the file 'INCLUDE/PETRO/FLUXNUM_0704.prop'.

I don't know if Eclipse cares about the case of the keywords, but
opm-parser currently does for sure. (If Eclipse turns out to be
case-insensitive, the easiest fix for us is to just make all keywords
ALL_UPPERCASE...)
rev
decorate the deck object with warnings instead of throwing exceptions for some parsing problems
fixup! change the parsing of raw keywords