don't keep a gdb-specific date

don't keep a gdb-specific date

Right now there are two nightly commits to update a file in the tree
with the current date.  One commit is for BFD, one is for gdb.

It seems unnecessary to me to do this twice.  We can make do with a
single such commit.

This patch changes gdb in a minimal way to reuse the BFD date -- it
extracts it from bfd/version.h and changes version.in to use the
placeholder string "DATE" for those times when a date is wanted.

I propose removing the cron job that updates the version on trunk, and
then check in this patch.

For release branches, we can keep the cron job, but just tell it to
rewrite bfd/version.h.  I believe this is a simple change in the
crontab -- the script will work just fine on this file.

This also moves version.in and version.h into common/, to reflect
their shared status; and updates gdbserver to use version.h besides.

	* common/create-version.sh: New file.
	* Makefile.in (version.c): Use bfd/version.h, common/version.in,
	create-version.sh.
	(HFILES_NO_SRCDIR): Use common/version.h.
	* version.in: Move to ...
	* common/version.in: ... here.  Replace date with "DATE".
	* version.h: Move to ...
	* common/version.h: ... here.
gdbserver:
	* Makefile.in (version.c): Use bfd/version.h, common/version.in,
	create-version.sh.
	(version.o): Remove.
	* gdbreplay.c: Include version.h.
	(version, host_name): Don't declare.
	* server.h: Include version.h.
	(version, host_name): Don't declare.
doc:
	* Makefile.in (POD2MAN1, POD2MAN5): Use version.subst.
	(GDBvn.texi): Use version.subst.
	(version.subst): New target.
	(mostlyclean): Remove version.subst.