[AD] Header splitup

["Vincent Penquerc'h" <Vincent.Penquerch@xxxxxxxxxx>]

Title: Header splitup

I now have a lovely new tree, but it's a hefty thing, so I'm not posting
it here. The contents of the new include/ tree are shown at the end of
the post.
I have two versions:
- a full diff (100 KB compressed, 800 KB tree)
- a tarball of include/ and a diff of the rest
since a diff of include is likely to be not very useful, and pretty much
everything was moved around.
This is based on the CVS version from Friday afternoon, so it won't
have all the patches applied this weekend.

Anyone who wants it, mail me privately, and tell me which version you
prefer.

Also fixes:
- unused var in vbeaf.c
- fixsqrt -> fsqrt, it was not compiling in C++ mode (might not work in
  Irix, as I believe this was done for Irix?)
- get_executable_name moved out of line, as it's pointless to have it
  inline and it would have made me include more headers in headers (yuck)

--
Vincent Penquerc'h