Treat the "Default" branch similarly to other branches

Currently the "default" branch treated differently from all of the other branches.

1. It would be nice to be able to rename the default branch to "master" or "trunk" anything else.
2. It would be nice if the dashboard (all plans) page showed information about other branches (not just default).
3. It would be nice if the "branches" page of a plan showed all branches (including default)

All the branches should be equivalent. In fact, you should be able to delete the "default" (first) branch and still have a plan.