Back out some changes to docs Makefiles

Commit ab0e9dbfa76e056f875e969c0d7b6e133ec75431 introduced some changes
to the documentation Makefiles designed to clean-up the process of
deciding which headers get scanned for the docs.

Unfortunately, the gtk-doc Makefile doesn't use HFILE_GLOB for actually
generating the docs -- only for knowing when it needs to redo the
generation.  Because of this, we need to use IGNORE_HFILES or otherwise
we get hundreds of symbols in the *-unused.txt files.

Revert the changes that that commit made to the docs Makefiles (but
leave the generation of the *-public-headers.txt files in place).

docs/reference/gio/Makefile.am

@@ -16,7 +16,7 @@ SCAN_OPTIONS=--deprecated-guards="G_DISABLE_DEPRECATED"
 DOC_SOURCE_DIR=$(top_srcdir)/gio
 
 BUILT_HFILES=gioenumtypes.h
-HFILE_GLOB=$(filter-out $(addprefix %/, $(BUILT_HFILES)), $(addprefix $(top_srcdir)/gio/,$(shell cat $(top_builddir)/gio/gio-public-headers.txt))) $(addprefix $(top_builddir)/gio/,$(BUILT_HFILES))
+HFILE_GLOB=$(top_srcdir)/gio/*.h
 CFILE_GLOB=$(top_srcdir)/gio/*.c
 
 # CFLAGS and LDFLAGS for compiling scan program. Only needed

docs/reference/glib/Makefile.am

@@ -19,11 +19,35 @@ SCAN_OPTIONS=--deprecated-guards="G_DISABLE_DEPRECATED" --ignore-decorators="GLI
 MKDB_OPTIONS=--sgml-mode --output-format=xml --name-space=g
 
 # Used for dependencies
-HFILE_GLOB=$(addprefix $(top_srcdir)/glib/,$(shell cat $(top_builddir)/glib/glib-public-headers.txt)) $(top_srcdir)/gmodule/*.h
+HFILE_GLOB=$(top_srcdir)/glib/*.h $(top_srcdir)/gmodule/*.h
 CFILE_GLOB=$(top_srcdir)/glib/*.c $(top_srcdir)/gmodule/*.c
 
 # Ignore some private headers
-IGNORE_HFILES = gwakeup.h
+IGNORE_HFILES = \
+	gdatasetprivate.h	\
+	glibintl.h		\
+	gbsearcharray.h		\
+	gmoduleconf.h		\
+	gunibreak.h		\
+	gunicomp.h		\
+	gunidecomp.h		\
+	gunichartables.h	\
+	glib_trace.h		\
+	libcharset.h		\
+	gdebug.h		\
+	gprintfint.h		\
+	gmirroringtable.h	\
+	gscripttable.h		\
+	glib-mirroring-tab	\
+	gnulib			\
+	pcre			\
+	update-pcre		\
+	gbufferprivate.h	\
+	gvariant-internal.h	\
+	gvariant-serialiser.h	\
+	gvariant-core.h		\
+	gvarianttypeinfo.h	\
+	gwakeup.h
 
 # Images to copy into HTML directory
 HTML_IMAGES =  				\

docs/reference/gobject/Makefile.am

@@ -20,9 +20,16 @@ SCAN_OPTIONS=--deprecated-guards="G_DISABLE_DEPRECATED" \
 MKDB_OPTIONS=--sgml-mode --output-format=xml --name-space=g
 
 # Used for dependencies
-HFILE_GLOB=$(addprefix $(top_srcdir)/gobject/,$(shell cat $(top_builddir)/gobject/gobject-public-headers.txt))
+HFILE_GLOB=$(top_srcdir)/gobject/*.h
 CFILE_GLOB=$(top_srcdir)/gobject/*.c
 
+# Headers to ignore
+IGNORE_HFILES = \
+	tests			\
+	gobject_trace.h		\
+	gatomicarray.h
+
+
 # CFLAGS and LDFLAGS for compiling scan program. Only needed
 # if $(DOC_MODULE).types is non-empty.
 INCLUDES = \