generate lib/ggv-sidebar/Makefile.

generate lib/ggv-sidebar/Makefile.

* configure.in: generate lib/ggv-sidebar/Makefile.

* lib/Makefile.am (SUBDIRS): add ggv-sidebar.

* lib/ggv-sidebar/ggvutils.h, lib/ggv-sidebar/ggv-prefs.h:
everything we need from the ggv files of the same name.

* lib/ggv-sidebar/ggvutils.c: plus their implementation.

* lib/ggv-sidebar/Makefile.am: add ggvutils.[hc], ggv-prefs.h.

* xpdf/Makefile.am: link with ggv-sidebar.

* xpdf/gpdf-view.cc: implement GgvDocument interface.
(gpdf_view_get_type): cannot use CLASS_BOILERPLATE with interfaces.
(gpdf_view_get_page_count, gpdf_view_get_page_names)
(gpdf_view_instance_init): for the interface.

* xpdf/tests/test-gpdf-view.cc: add tests for GPdfView.

* xpdf/tests/.cvsignore: ignore test-gpdf-view.

* xpdf/tests/Makefile.am: add new test, link with ggv-sidebar.