feat($compile): change directive's restrict setting to default to EA (el...

...ement/attribute)

Previously we defaulted just to A because of IE8 which had a hard time with applying css styles to HTMLUnknownElements.

This is no longer the case with IE9, so we should make restrict default to EA. Doing so will make it easier to create
components and avoid matching errors when creating new directives
Is there any reason why this couldn't be an element too, if we wanted?