build-image.sh: Customize the rootfs a bit

Get rid of the panda in the hostname, and disable somes services for
faster performance on the somewhat low powered A10 devices.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
README: Add the missing of a plymouth splash screen to Know Issues

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
build-boot-root.sh: Update tags

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The selinux issues have been fixed

Yeah!

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
build-boot-root.sh: Update tags

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
README: various improvements to README

Signed-off-by: Hans de Goede <hdegoede@redhat.com>