gem5 cache automate benchmarks, and remove results that were scattered all over.
Move console fun under linux kernel section, since not important enough
for getting started.
Set arch x86_64 by default through common on all scripts.
Document that X11 mouse is not moving.
Convert x='' to x= on all scripts, and also fix case ;; indentations.
Add dummy value to QEMU's -trace enable= to prevent warning.
Expand built-in package choice rationale.
Most of it was present inside buildroot/output.* and the rest scattered
on top level.
This came about for the n-th time when we were reviewing QEMU trace file
locations.
On one hand, it would be cool to have per arch traces.
This made buildroot/output.${arch}~/ a natural choice.
But on the other, those traces have nothing to do with Buildroot,
and could potentially interfere with Buildroot build files.
It also feels nicer to have buildroot/ pristine source code only,
and keep all output under a single directory out/
This is necessary because qemu and gem5 now use the same build folder.
Separate ./run -e and -f for kernel options before and after the ' - '.
This was already the better thing to do when -E was introduced,
but lkmc_nonet prompted me to do it nicer now.
Use the common script to find the out_dir on every toplevel script.
Include usage man pages on README.
