Adjust to recent changes to gnulib bootstrap.

* .cvsignore, build-aux/.cvsignore, doc/.cvsignore, etc/.cvsignore:
* examples/calc++/.cvsignore, lib/.cvsignore, m4/.cvsignore:
* po/.cvsignore, runtime-po/.cvsignore, src/.cvsignore:
* tests/.cvsignore: Remove; I don't use CVS to maintain Bison
anymore and don't know of anybody else who does.  If someone needs
these files, they can resurrect them.
* .gitignore, build-aux/.gitignore, doc/.gitignore, lib/.gitignore:
* m4/.gitignore, po/.gitignore, runtime-po/.gitignore:
Omit leading '/', since bootstrap omits it.
Adjust file names to match current contents better.
* bootstrap: Sync from gnulib: this contains the new gnulib_mk_hook
installed just for us.
* bootstrap.conf (excluded_files): Don't exclude codeset.m4,
glibc21.m4, inttypes_h.m4, size_max.m4, xsize.m4, as they are now
needed somehow.  Don't have time to look into why.
(gnulib_modules): Change malloc to malloc-gnu.  Do we really assume
the GNU malloc behavior, where malloc (0) != NULL unless we're
out of storage?  If not, we can omit malloc-gnu; but for now I left
it in to be safe.
(vc_ignore): Remove.
(gnulib_mk_hook): New function.
* README-hacking: Renamed from HACKING, since gnulib bootstrap now
uses that convention.

bootstrap.conf

@@ -20,7 +20,7 @@ gnulib_modules='
   announce-gen argmatch assert config-h c-strcase configmake dirname
   error extensions fopen-safer gendocs getopt-gnu gettext
   git-version-gen hash inttypes javacomp-script javaexec-script
-  maintainer-makefile malloc mbswidth obstack pipe quote quotearg
+  maintainer-makefile malloc-gnu mbswidth obstack pipe quote quotearg
   realloc-posix stdbool stpcpy strerror strtoul strverscmp unistd
   unistd-safer unlocked-io update-copyright unsetenv verify warnings
   xalloc xalloc-die xstrndup
@@ -45,28 +45,25 @@ XGETTEXT_OPTIONS_RUNTIME=$XGETTEXT_OPTIONS'\\\
 # Gettext supplies these files, but we don't need them since
 # we don't have an intl subdirectory.
 excluded_files='
-    m4/codeset.m4
     m4/glibc2.m4
-    m4/glibc21.m4
     m4/intdiv0.m4
     m4/intl.m4
     m4/intldir.m4
     m4/intmax.m4
-    m4/inttypes_h.m4
     m4/lcmessage.m4
     m4/lock.m4
     m4/longdouble.m4
     m4/signed.m4
-    m4/size_max.m4
     m4/uintmax_t.m4
     m4/ulonglong.m4
     m4/visibility.m4
-    m4/xsize.m4
 '
 
-# In directories like lib/, m4/, and po/, generate both these files because we
-# still try to support CVS emulation.
-vc_ignore='.cvsignore .gitignore'
+# Massage lib/gnulib.mk before using it later in the bootstrapping process.
+gnulib_mk_hook()
+{
+  etc/prefix-gnulib-mk $1
+}
 
 bootstrap_epilogue()
 {