Massive update. The highlights:
o dramatically cut memory usage by writing better, less intertwingled
code.
o implement booting off mmc/sd cards (sd only tested one at the moment)
o start to split out board specific stuff for boot2.
changes in the future. This helps with getting started and to
overcome the really sucky level of granuality this timeout has in
getc. A timeout of 1 means 'wait until top of next second' rather
than 'wait for at least a second'.
Make this compile, assuming that you have linux installed in a
sensible place. tag_list is disabled by default, since we don't
distribute linux, but it is desirable to allow the boot loader to boot
Linux or FreeBSD (mostly for testing).
o Use a directory layout that is more akin to the i386 boot layout.
o Create a libat91 for library routines that are used by one or more
of the boot loaders.
o Create bootiic for booting from an iic part.
o Create bootspi for booting from an spi part.
o Optimize the size of many of these routines (especially emac.c). Except
for the emac.c optimizations, all these have been tested.
o eliminate the inc directory, libat91 superceeds it.
o Move linker.cfg up a layer to allow it to be shared.
