(storm) Keep kernel log from bootup and expose it in the kernelfs

[perlun]

Right now, the messages printed to the screen on startup before the console server has cleared the screen and set up a video mode gets wiped out once that happens. This is not so great. They should be available to the log server, and printed on its kernel log console.

A simple way to do this is to use a fixed buffer (say, 80x50=4000 bytes) and ensure to rotate away old content if this is not enough. (Or just hang the system startup, if we are lazy...)