move version.in from gdb/common back to gdb

This reverts part of the earlier version.in change.  It moves
version.in back to the gdb directory.  This works around the CVS bug
we've found.

gdb
	* Makefile.in (version.c): Use version.in, not
	common/version.in.
	* common/create-version.sh: Likewise.
	* common/version.in: Move...
	* version.in: ...here.
gdb/doc
	* Makefile.in (version.subst): Use version.in, not
	common/version.in.
	* gdbint.texinfo (Versions and Branches, Releasing GDB):
	Likewise.
gdb/gdbserver
	* Makefile.in (version.c): Use version.in, not
	common/version.in.
sim/common
	* Make-common.in (version.c): Use version.in, not
	common/version.in.
	* create-version.sh: Likewise.
sim/ppc:
	* Make-common.in (version.c): Use version.in, not
	common/version.in.