[dfdl-wg] Revised charter

I have put up the revised charter proposal at: https://forge.gridforum.org/projects/dfdl-wg/document/DraftRevisedCharte r/en/1 Part of the aim here was minimum changes. I have basically updated contact information and changed the document descriptions and milestones in accordance with our discussion at the F2F. The rest I left because it did not seem to have changed in any important ways. If you spot any problems please let me know by the end of the week. If there's nothing unresolved I will submit it to GGF on Friday. Thanks, Martin