Sandbox is a library (and helper utility) to run programs in a
"sandboxed" environment. This is used as a QA measure to try and
prevent applications from modifying files they should not.

For example, in the Gentoo world we use it so we can build applications
as root and make sure that the build system does not do crazy things
outside of its build directory. Such as install files to the live root
file system or modify config files on the fly.

For people who are familiar with the Debian "fakeroot" project or the
RPM based "InstallWatch", sandbox is in the same vein of projects.
