Remove script stamping in lib-src/

Remove script stamping in lib-src/

rcs2log no longer needs it, and grep-changelog never really has
(nothing in Emacs runs that, I don't know why Emacs includes it, if you
are using an uninstalled out-of-tree build you can just as easily run
it from the source directory).

* lib-src/Makefile.in (STAMP_INST_SCRIPTS, STAMP_SCRIPTS, insrcdir)
(stamp-rcs2log, stamp-grep-changelog): Remove.
(all, clean): Remove references to stamps.

* .bzrignore: Do not ignore lib-src/stamp*.