"image" was an alias for "qemu-image".
I want to add an `image` userland utility, which clashes with that
shortname.
So remove the existing "image" target. It was just an alias for
"qemu-image".
If you use serenity.sh to build, nothing changes. This only affects you
if you run ninja manually -- you now have to say `ninja qemu-image` to
build the disk image.
'bootmode' now only controls which set of services are started by
SystemServer, so it is more appropriate to rename it to system_mode, and
no longer validate it in the Kernel.
Bootmode used to control framebuffers, panic behavior, and SystemServer.
This patch factors framebuffer control into a separate flag.
Note that the combination 'bootmode=self-test fbdev=on' leads to
unexpected behavior, which can only be fixed in a later commit.