Augment the generate distclean target (fixes #14)

Makefile.am

@@ -2,3 +2,68 @@
 
 EXTRA_DIST = autogen.sh
 SUBDIRS = src include docs visualc_net
+
+# Per the auto-tools clean guidelines:
+# https://www.gnu.org/savannah-checkouts/gnu/automake/manual/html_node/Clean.html#Clean
+#
+# "if configure built it, then 'distclean' should delete it", however the generated
+# _distclean_ target misses many files generated by ./configure, so we augment them
+# here.  We also add those files generated by automake and autoconf to ensure 'distclean'
+# reverts the directory back to its original as-distributed source tree.
+#
+# (note: with recursive makefiles, these files could be defined as individual distclean-local:
+# targets inside each sub-directory's Makefile.am, however listing them in one target here
+# is easier manage as they can all be seen at once.)
+
+distclean-local:
+	-rm aclocal.m4
+	-rm autom4te.cache
+	-rm build.log
+	-rm compile
+	-rm config.guess
+	-rm config.h.in
+	-rm config.log
+	-rm config.sub
+	-rm configure
+	-rm depcomp
+	-rm docs/Makefile.in
+	-rm include/Makefile.in
+	-rm install-sh
+	-rm Makefile.in
+	-rm missing
+	-rm -rf autom4te.cache
+	-rm -rf src/cpu/.deps
+	-rm -rf src/debug/.deps
+	-rm -rf src/.deps
+	-rm -rf src/dos/.deps
+	-rm -rf src/fpu/.deps
+	-rm -rf src/gui/.deps
+	-rm -rf src/hardware/.deps
+	-rm -rf src/hardware/mame/.deps
+	-rm -rf src/hardware/serialport/.deps
+	-rm -rf src/ints/.deps
+	-rm -rf src/libs/gui_tk/.deps
+	-rm -rf src/misc/.deps
+	-rm -rf src/shell/.deps
+	-rm src/cpu/core_dynrec/Makefile.in
+	-rm src/cpu/core_dyn_x86/Makefile.in
+	-rm src/cpu/core_full/Makefile.in
+	-rm src/cpu/core_normal/Makefile.in
+	-rm src/cpu/Makefile.in
+	-rm src/debug/Makefile.in
+	-rm src/dos/Makefile.in
+	-rm src/fpu/Makefile.in
+	-rm src/gui/Makefile.in
+	-rm src/hardware/Makefile.in
+	-rm src/hardware/mame/Makefile.in
+	-rm src/hardware/serialport/Makefile.in
+	-rm src/ints/Makefile.in
+	-rm src/libs/gui_tk/Makefile.in
+	-rm src/libs/Makefile.in
+	-rm src/libs/zmbv/Makefile.in
+	-rm src/Makefile.in
+	-rm src/misc/Makefile.in
+	-rm src/platform/Makefile.in
+	-rm src/platform/visualc/Makefile.in
+	-rm src/shell/Makefile.in
+	-rm visualc_net/Makefile.in