examples: Fix 'make dist'.
* gettext-tools/examples/hello-c/m4/Makefile.am (EXTRA_DIST): Add all files
that are brought in by 'autopoint'.
* gettext-tools/examples/hello-c-gnome/m4/Makefile.am (EXTRA_DIST): Likewise.
* gettext-tools/examples/hello-c-gnome3/m4/Makefile.am (EXTRA_DIST): Likewise.
* gettext-tools/examples/hello-c++/m4/Makefile.am (EXTRA_DIST): Likewise.
* gettext-tools/examples/hello-c++-kde/m4/Makefile.am (EXTRA_DIST): Likewise.
* gettext-tools/examples/hello-c++-gnome/m4/Makefile.am (EXTRA_DIST): Likewise.
* gettext-tools/examples/hello-objc/m4/Makefile.am (EXTRA_DIST): Likewise.
* gettext-tools/examples/hello-objc-gnome/m4/Makefile.am (EXTRA_DIST): Likewise.
