* Get rid of the RCS Header stuff.  They're meaningless in git.
 * Add public domain comment to some of the files if the only comment
   was the RCS header.

reg_NARGS macro on these targets and use SC_REG to replace open-coded
assignments to platform specific sigcontext members in interrupt.c and
os-common.c.  This code could be simplified further by merging the x86
and AMD64 cases into the general case.

.indent.pro.

lisp.c into the correct <foo>-os.h files.

code which were previously conditionalized on :FreeBSD, are now
conditionalized on :BSD instead, with the :BSD feature now implying a
4.4BSD(lite2) derived OS.  This should make future BSD-ports easier.
FreeBSD and OpenBSD are differentiated by having either :FreeBSD or
:OpenBSD on the features list.

Currently the OpenBSD port does not have working ELF support, because
OpenBSD 2.9 is still non-ELF by default.  So don't put ELF on the
features list when building for OpenBSD, or fix the code to work
correctly in this case instead.