loggerhead.apps.config clobbers BranchWSGIApp.branch_url method

(Thanks to Spaz in #bzr for noticing this.)

From loggerhead.apps.config:

Project._add_view builds up a dict in self.view_data_by_name[view_name], including one key called "branch_url", which points to a string. Later, Project.view_named creates a BranchWSGIApp object and sets the contents of the dict as attributes on the BranchWSGIApp object. This means that the branch_url method is now a string, so BranchWSGIApp.app explodes when it attempts to call it.

See a traceback at http://pastebin.ca/1421449

This bug isn't new, but branch_url wasn't used anywhere until r335 of the trunk, so it wasn't noticed. Now start-loggerhead is broken. Whoops. :\

I'm not sure what the best solution is. I don't know the start-loggerhead-related code. The simplest solution is renaming the method to "public_branch_url" or something, but setting a bunch of attributes on another object seems bizarre. (Like I said, I don't know the code, so it might actually make sense.)