fakeroot: add head

Adds a HEAD build to Fakeroot, specifies the non-functional
status of Fakeroot on Yosemite in the stable release, moves to the
upstream preferred package page, adds a slightly faster mirror as the
main url & uses the standard url as the mirror.

Closes #33532.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>