Universalize {{view}} helper quoteless binding syntax, prevent id binding

The quoteless shorthand binding syntax, which you may
remember from the `{{input}}` helper or views/components
wrapped in `Ember.Handlebars.helper`, has been moved
into the `{{view}}` helper, which universalizes the syntax
for any helpers that eventually invoke the `{{view}}` helper.

So now you can do:

    {{#view 'someView' foo=bar}}
      Bound foo property: {{view.foo}}
    {{/view}}

Instead of having to do `fooBinding="bar"`

Furthermore, specifying `id=someProperty` will just perform a
one-time lookup for `someProperty`, rather than creating a binding.
Closes #3490.
[BUGFIX beta] Soft-deprecate mixed binding syntax in view helper

Someone on IRC got bit by 97dc83b4a5f869c9f86fe8144d4faf168ca41a50,
and I'm sure there will be others, due to doing something like
{{view Ember.View somethingBinding=unquotedPropertyPath}}, which
with the above commit create a binding on the view object
from `somethingBinding`=>`unquotedPropertyPath`, vs. the
(incorrectly but understandably) expected
`something`=>`unquotedPropertyPath`. This commit will support
the mixed syntax for now but warn the user about it.