Modify parse logic to check for a files attribute and parse it

[marutypes]

As discussed in issue #51

Change Summary

• Modified logic in maybeParseGenericCustomElement to check for a files attribute on custom elements instead of deferring to the maybeParseFileInput function.
• Modified the anonymous iterator for form parsing to remove explicit calling of maybeParseFileInput and to pass the parseFileInputs flag along instead of predicating behavior based on it.
• Left the old specific logic as it was used in other places (made minimum viable change). This might want to be refactored.

Testing Performed

• Manual functional testing using <image-input> as discussed in referenced issue (passed)
• Ran the test suite (passed)

[rnicholus]

Thanks for this. I'll need to spend some time looking over the changes a bit closer.

Before releasing, I'll need to:

• remove the old file input handling code

[marutypes]

NP. I'll be using it in a project, so I'll update it if I encounter any issues.

[rnicholus]

@TheMallen When you get some time, please take a look at the modified ajax-form.html in the fix/file-input-integration branch. I pulled your pull request into this branch and removed the redundant file-input code.

If it checks out, I'll end up releasing this as ajax-form 1.5.3.

[marutypes]

I've been using the modified version and haven't had any problems. Yours looks fine to me 👍

[rnicholus]

Released as part of 1.5.4.