Change input selector to exclude the few that don't use common styling

[khamer]

Here's a PR For Issue #258 - as schirrel hasn't had a chance to get to it. I'm not sure if I think this is easier to read or more performant, but wanted to offer up the solution that @cjpatoilo was looking for.

[Sancxo]

Hi guys,

I don't understand why this PR is not validated 2 years after ?

Actually it seems to fix a little issue I have : I made a form with, at the end, an input of type "file" with the submit button just after it; because the input[type="file"] is not present in the list of selectors in the forms style sheet, it doesn't have the "width: 100%" property as the others inputs, and because the button is specified as "inline-block" by Milligram I have my input "file" and the button on the same line. So I manually added the "width: 100%" for my input file in a CSS file to have them in two different lines, it's no big deal but the @khamer would naturally fix that.

@cjpatoilo: Is there still maintainers to the project to review and merge ?