fix(input): use all supported attributes on both textareas and inputs

[Manduro]

Short description of what this resolves:

Checking out the amazing keyboard/input refactor by @manucorporat, I came across some inconsistencies in the attributes that are supported for ion-input and ion-textarea.

Changes proposed in this pull request:

• Add autocomplete and autocorrect attributes for which the Input()s already exist.
• Add maxlength, spellcheck and autocapitalize on ion-textareas as well.

Ionic Version: 3.x (nightly)

[manucorporat]

You right, thanks! will review it! in fact I think we should take a different approach in the future, since this does not scale really well hahah adding more and more attributes...

[ryanhalley]

Hi. Regarding maxlength for ion-input and ion-textarea, was it your intention that the behaviour be: user types text and is not restricted during data entry, they leave the field, and field contents are then truncated to maxlength?
I was expecting the fields to prevent me typing in excess of maxlength during text entry, like HTML input does; could you please change the behaviour to this expected convention?

To be clear, I am testing with livereload (ionic cordova run android -cl), and release builds, and neither of them restrict during data entry.