ExtUtils::InstallPaths tries to make install path resolution as easy as
possible.

When you want to install a module, it needs to figure out where to
install things. The nutshell version of how this works is that default
installation locations are determined from ExtUtils::Config, and they
may be individually overridden by using the install_path attribute. An
install_base attribute lets you specify an alternative installation root
like /home/foo and prefix does something similar in a rather different
(and more complicated) way. destdir lets you specify a temporary
installation directory like /tmp/install in case you want to create
bundled-up installable packages.
