Update nss_nonlocal to 2.1

- Support Automake 1.12.
- Guard one-time initialization with memory barriers.
- Make initgroups_dyn succeed when adding only magic groups.



git-svn-id: file:///mit/scripts/svn/trunk@2432 db9d59ff-b01e-0410-9b1a-cd9a8c06840f


git-svn-id: file:///mit/scripts/svn/trunk@2433 db9d59ff-b01e-0410-9b1a-cd9a8c06840f