Formalize language in charter

This is an addition to #49 that adds more formal language to the list of charged tasks.

I have half a mind to remove the `not been widely implemented` as well. If it's not implemented, this means it's up to the implementations to get it so.  Only Firefox supports [SVG favicons](http://caniuse.com/#feat=link-icon-svg) so far, if this charter was for W3C would you remove it from the spec, or expect the other browsers to work towards complying to the spec.

Hope you like the changes!

If merged this would close #49 expectedly