Add back the Ubuntu "Memory and Swap Accounting" section that was lost when the "Kernel" page was culled

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #4251 from tianon/add-back-grub-info

Add back the Ubuntu "Memory and Swap Accounting" section that was lost when the "Kernel" page was culled