Add ability to pass grommet version to components and props

[jcfilben]

This idea stemmed from discussion on this pull request: #416

It would be nice if we had the ability to pass the version of grommet that components and props were included in. From here we can adjust messaging for components and props based on what version they were added in and what version of grommet is the latest. For example: 'new is stable branch' or 'new on version x.y.z'