Editor role revisions

Revised based on IRC discussion.  Major changes:

* Instead of Author(s) with random Contributors, there is now an Editor managing the proposal on the creator side backed by 0 or more Contributors.  The word "Author" has been largely removed to avoid ownership/territoriality potential.

* The Pre-Draft phase has been clarified to be a time to assemble a working group, not to develop an entire proposal.  The minimum for a Draft Vote is explicitly specified to be the statement of problem and vague hand-wavy solution, since that gets the proposal into a formal process ASAP (or kills it as not something FIG wants to consider ASAP).  

I also make some related language tweaks along the way, but nothing major, I think.  Oh yeah, and fixed trailing whitespace. (Grr, fix your editors.)