maint: ignore more build artifacts

.gitignore

@@ -4,18 +4,22 @@
 /.pc/
 /.version
 /ChangeLog
+/GNUmakefile
+/ID
 /INSTALL
 /VERSION
 /aclocal.m4
 /autom4te.cache/
 /build-aux
+/config.cache
 /config.h
 /config.hin
-/config.hin~
 /config.log
 /config.status
 /configure
+/doc
 /lib
+/maint.mk
 /patch-*.tar.bz2
 /patch-*.tar.bz2.sig
 /patch-*.tar.gz
@@ -26,5 +30,4 @@
 /stamp-h1
 Makefile
 Makefile.in
-build-aux
-doc
+TAGS

m4/.gitignore

@@ -68,6 +68,7 @@
 /safe-read.m4
 /safe-write.m4
 /setenv.m4
+/signal_h.m4
 /size_max.m4
 /ssize_t.m4
 /stat-time.m4