It seems that the main GNU download site has issues in some places
outside the U.S., so we'll use the provided "ftpmirror.gnu.org" to pick
a nearby mirror.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>
This commit also streamlines the installation process due to changes in
dependencies and contains a fix for Lion BLAS issues.
ClosesHomebrew/homebrew#6649.