Removed generated header file from git
Do not attempt to copy stage2 binaries to non-existant directory

We'll leave it up to the developer to copy the binaries if needed;
the stage1 build doesn't copy the produced binaries either.
Remove execute permissions from source files
Removed whitespace after backslash in header

This avoids lots of compiler warnings.
Preserve the v1 and a0 registers in the stage 1 firmware

The C calling convention allows these registers to be trashed, but the
routine in the Boot ROM we're returning to expects their values to be
preserved.

This fixes an issue with the system leaving USB boot mode depending on
the values that GCC happens to leave in those register.
Rebuilt firmware for all SDRAM types

Previously only the DDR2 firmware binary was included in the fw/
directory, now the DDR1 and MDDR binaries are added to that.
Create "fw/hand.bin" and "fw/hand.fw_args.bin" with user write permissions

This allows them to be overwritten by fw_cfg_tool. Currently the
top-level script never does that, but that's going to change.
Add support for easy switching between multiple boards

Put the board name in the file name of all generated files, so there
is no risk of mixing up parameter blocks or patched binaries between
them.

Also introduced the "RAMTYPE" option in the board configuration;
previously DDR2 was hardcoded in several scripts.

Minor cleanup in fw_cfg_tool.c: zero struct before parsing, so there
won't be any random data in unused fields.
Add config files for the various GCW Zero hardware revisions

Also made the most recent board default, since that will be the
hardware that most users will receive.