Warn if colon shorthand is used on v-if/v-html/etc.

What problem does this feature solve?

I just spent way too long debugging something really weird until I realized I accidentally wrote :v-if instead of v-if.

A warning when wrongly using shorthands like : on "native" vue attributes could prevent this bad experience easily.

What does the proposed API look like?

:v-if="foo"

--> console.warn("You specified v-bind:/ v-on: or a corresponding shorthand on a Vue attribute like v-if or similar. Usually this does not make sense.)