fishgen: Fix conflicting flag column names

[Kissaki]

'c' and 'C' conflicted, leading to get c getting the C column

Clear out 'complete ' earlier, in tokenize-complete-lines.

Parse and pair flags without values as well.

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Based on #1122

[Kissaki]

I have four commits but don't want to lose the distinct history of the changes by squash merges. Handling these as separate PRs is a hassle. Isn't merging with merge commit something that could be done where it makes sense?

I'm used to structuring my commits into a descriptive history, and sectioning bigger changes step by step, where each step makes sense on its own. The PR title and description then becomes the merge commit, and describes the whole set of changes.

[fdncred]

Doing your commits this way is helpful to reviewers but we squash and merge in all of our repos.

[Kissaki]

is rebased with "conflict" resolved