Don't version-control generated file `grammat-wy.el`

Don't version-control generated file `grammat-wy.el`

This file is needed for CEDET's bootstrap, tho, so we now keep a copy of it
under version control in `gram-wy-boot.el`, very much like we do with
the `ldefs-boot.el` copy of `loaddefs.el`.

* lisp/cedet/semantic/grm-wy-boot.el: Rename from
`lisp/cedet/semantic/grammar-wy.el`.

* lisp/cedet/semantic/grammar.el: Load `grm-wy-boot.el` if
`grammar-wy.el` hasn't been generated yet.

* admin/update_autogen: Also refresh `grm-wy-boot.el`.

* admin/grammars/Makefile.in (WISENT): Add `grammar-wy.el` to the
generated files.

* .gitignore: Add `grammar-wy.el`.