provide better weights for /project/issues and /project/user menu items

in testing the http://drupal.org/project/drupalorg_testing install profile (which defaults to garland, which actually displays secondary menu items), i noticed that the menu tree at [site]/project is a little silly: "Issues" and "My projects" are just mixed in with all the actual project types, totally random, based on taxonomy weight (defaulting to 0 everywhere) and alphabetical order. ;) seems like we should at least put these 2 issue-related menu items at a higher weight than any possible taxonomy terms, so they're at least grouped together. maybe these 2 shouldn't really be real menu items at all, and should instead just be callbacks? dunno. it's not clear to me what's the best way to handle these menu items.

frankly, the whole overloading of /project is the root of much evil. :( but, that's a bigger problem we can't really change now. ;)