Most input -> button convertion

[bbannon]

Since Craig is rewriting install/index.php, I didn't do those. But, I think I got the rest of converting <input> to <button>

[bbannon]

This really has nothing to do with buttons, but I didn't want to reopen an old pr.

Isn't phpunit a debug tool for developers? Do end users need a copy of it from composer?

Also, I'm beginning to see the advantages of moving all the source files into 'webcalendar/source/' for devs to work on.
Then copying ONLY the files end users need, ALL minified (except *.txt files for the moment), to 'webcalendar/dist/' to be packaged as the 'distro.zip' file. I've been testing that. It's really not very disruptive to have a couple of subfolders that 'the code' uses, but people won't really see. It would be a huge pr, but only once. And the distro.zip would be about half the current size. Even less if we can figure out how to copy only the various translation files, captcha/ckeditor/phpmailer/ours that each user actually needs.

[craigk5n]

End users don't need phpunit, and it's not included in the releases. Releases currently only include what is listed in release-files which does not include the "vendor" directory.

[craigk5n]

See release.yml to see how releases are created.

[bbannon]

I asked because I don't see a version of composer.json that leaves out that line.