us up to version 2.17.50.20070703, at the last GPLv2 commit.
Amongst others, this added upstream support for some FreeBSD-specific
things that we previously had to manually hack in, such as the OSABI
label support, and so on.
There are also quite a number of new files, some for cpu's (e.g. SPU)
that we may or may not be interested in, but those can be cleaned up
later on, if needed.
Binutils has a "contrib" subdirectory - thus flattening cannot happen
without renaming the upper level contrib directory in a first pass.
Also, don't record this move and remove any keyword expansion.