highlight jsdoc optional param and optional param with default value

[ryanoasis]

[amadeus]

This looks good, but the branch has some weird merge commits that worked their way in.

Probably the easiest way to to fix would be to create a branch that is all up to date with this repo's develop. Assuming you added this repo as a new remote (git remote add source git@github.com:pangloss/vim-javascript.git), you would do:

git fetch source
git checkout source/develop
git checkout -b new-branch-name

Then simply cherrypick that single commit onto it:

git cherry-pick 9336404fac4549928ba1e8876cc4463677d3ce24

Then push that you branch to your repo:

git push -u origin new-branch-name

and then submit a PR using that new branch.

[ryanoasis]

@amadeus yep I did notice that. thanks. i'll do that.

[davidchambers]

Superseded by #225