Revert "also eat keywords containing lowercase letters"

this was inadvertedly merged. the real fix is to make the parser
case-insensitive...
make the parser case-insensitive

i.e., make keywords ALL_UPPERCASE before using them because Eclipse
seems to be case-insensitive (although this is one of its undocumented
features...)
Merge pull request #349 from andlaus/make_it_case_insensitive

make the parser case-insensitive