Directory setup functions override pages created in WordPress

[johnbillion]

When you create a page in a member blog with a slug that matches a BP component (groups, members, or blogs), BP will kick in and try to load the directory listing of that component instead of allowing WordPress to show the page.

Steps to reproduce:

1. In a blog on example.com, publish a page called 'Groups'. This will give you a page at example.com/myblog/groups (or myblog.example.com/groups).
2. Attempt to visit the page. BuddyPress will try to load the groups-directory.php or plugin-template.php file from the current template and give an error, instead of letting WordPress show the page in the blog's theme.

I'm not sure if this is a problem with the priority of groups_directory_groups_setup() being too high, or whether this is a problem with $bp->current_component being populated when it shouldn't. Or something else.

[apeatling]

(In [1253]) Fixes #604