Versioning proposal

* I believe our next release should be considered 1.0. Only major
  releases should make incompatible URLs and I believe we should be free
  to do that for our next "release". This means we can be free to make a
  0.1 stable release if we want that remains URL compatible. I don't
  know why right now. I just feel we should be working towards 1.0,
  not 0.1 when we already have a release. Please feel free to reject.
* For non-tagged updates, I'm thinking the extra-version should be
  something like "wip" to show that it isn't published to the main
  documents site yet.
* I think we should pull the major/minor/extra from the tag, instead of
  branch, and expect it to be used appropriately.
* I know it isn't the prettiest thing, but having a date for the
  patchlevel is super easy to automate and super easy to understand. I
  trust Robert's experience on this.
* I don't know the real purpose of VERSION_TWEAK, but it will be updated
  in case of more than one commit in a day.