Clean up the "Region 1" related definitions, and define load addresses,
max load size, and max total size for as many boot block types as we can.
(types = unified, primary, secondary). We can't always define all
values for all boot blocks, though.
Make CPP flags selection less gross.
Use objcopy rather than headersize (yay, evil gets a stake to the heart!).
Use a little shell script to verify that the sizes of the boot blocks are OK.
Do not compile too much more of libsa than we actually have to.
