If a word is made up of multiple word separator characters:
$ a b::<TAB> # CWORDS are: a, b, and :: (correct)
__reassemble_comp_words_by_ref() couldn't handle this. It assumed CWORDS were:
$ a b::<TAB> # CWORDS: a, b, : and : (but they're not)
Added test case for this. To run the automated tests:
./runUnit _get_cword.exp