Revision 399

Initial checkin for supermicro p4dc6
This also includes a bunch of my pending work including
- Updated serial code so we can compile in different serial port speeds
- Updates to the build system so that:
  - Makefile.settings holds all of the settings of the config variables
  - ldoptions and cpuflags are generated automatically with perl scripts
  - src/config/Config holds all of the architecture neutral make file settings
- Initial work on the P4 including how to use cache as ram
- Update to the ioapic code for the P4 because it delivers irqs on the system
  bus instead of an out of band bus
- Updated version of printf that doesn't need an intermediate buffer
  - logbuf_subr now handles the case when we want to use a log buffer
- video_subr handles the preliminary code for writing to a video device.
- Pending changes for the L440GX are merged in as well (hopefully I haven't
  messed then up since they were written).