- Allows uid switching as a normal user.

- Start any application making it believe it is running as root.

- Support for user/group changing in the local thread using the syscalls
  (like glibc).

- More precisely this library intercepts seteuid and related calls, and
  simulates them in a manner similar to the nss_wrapper and socket_wrapper
  libraries.

Some projects like a file server need privilege separation to be able to switch
to the connection user and do file operations. uid_wrapper convincingly lies to
the application letting it believe it is operating as root and even switching
between UIDs and GIDs as needed.