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. Note that
this patch causes the parser to bail out on the original Norne deck
once the module gets improoved sufficiently to detect the misspelled
'fluxnum' keyword. (which currently does not seem to be recognized,
probably due to some bug...)