The JavaScript involved wasn't working since we removed the disable-date
attribute in commit 73ff6881.
We're also improving the JavaScript in two ways:
First, we trigger the `change` event immediately, so when the page loads
date fields are disabled when phases are disabled.
And second, we don't remove the selected dates when disabling a phase,
so disabling it and enabling it again will keep the selected values.
For now we're only adding rules related to spacing and double quotes,
following the same rules we use in Ruby, which are the same rules
CoffeeScript followed when compiling these files.
We're also using the recommended ESLint rules, which will warn us about
many JavaScript common pitfalls, the `strict` rule which enforces using
strict mode, and the `no-console` rule, which will prevent us from
shipping code meant for debugging.
Although it's arguably more common to use the JSON format to define
these rules, I've chosen YAML because it's the format we use in all our
linters.
These statements were automatically added by CoffeeScript.
I'm only removing the obvious cases; there might be more cases where the
`return` statement isn't necessary.
