Revert "Revert "add default values required to make it possible to terminate keywords early""

This reverts commit 41dbe397db56e547f254f3b0302440b8f7a00db5.
Revert "make the parsing stage pass even if non-defaultable items have been defaulted"

This reverts commit 5ce5a3539641ac6eac9362d9c2b8a09084f9c35b.
add pseudo default values for more items

this is required by the Norne deck. the EQLOPTS keyword seems weird,
though, because its records seem to have a variable number of items...

for most of these the RM says that if nothing is specified, a value of
another item should be used. some items even have legitimate
defaults, but they are only mentioned in the prose of the RM's item
description. (e.g.the wetting_phase_flag item of the EHYSTR keyword...)
Merge pull request #390 from andlaus/fix_undefaultable_items

Fix undefaultable items