Add configuration checks to build system

* targets.mk: Add targets "config", "config-test", "config-exe",
  "config-cmd", "config-all" and "config-eol" (all .PHONY).  These
  echo various configuration dependent variables so they can be more
  easily checked for correctness.

* Makefile: Document the new targets, "config" with "help" and the
  rest with "helpall".

Makefile

@@ -61,6 +61,17 @@ helpall::
 	$(info make cleantest     - remove check remnants)
 	$(info make clean-install - remove previous Org installation)
 	$(info )
+	$(info Configuration Check)
+	$(info ===================)
+help helpall::
+	$(info make config        - check main configuration)
+helpall::
+	$(info make config-test   - check test configuration)
+	$(info make config-exe    - check executables configuration)
+	$(info make config-cmd    - check command configuration)
+	$(info make config-all    - check all configuration)
+	$(info make config-eol    - check all configuration, mark end-of-line)
+	$(info )
 	$(info Documentation)
 	$(info =============)
 help helpall::

targets.mk

@@ -23,10 +23,36 @@ ifneq ($(GITSTATUS),)
 endif
 
 .PHONY:	all oldorg update update2 up0 up1 up2 compile $(SUBDIRS) \
-		check test install info html pdf card doc docs $(INSTSUB) \
-		autoloads cleanall clean cleancontrib cleanutils cleanrel clean-install \
-		cleanelc cleandirs cleanlisp cleandoc cleandocs cleantest
-		compile compile-dirty uncompiled
+	check test install info html pdf card doc docs $(INSTSUB) \
+	autoloads cleanall clean cleancontrib cleanutils cleanrel clean-install \
+	cleanelc cleandirs cleanlisp cleandoc cleandocs cleantest \
+	compile compile-dirty uncompiled \
+	config config-test config-exe config-all config-eol
+
+CONF_BASE = EMACS lispdir infodir datadir testdir
+CONF_TEST = BTEST_PRE BTEST_POST BTEST_OB_LANGUAGES BTEST_EXTRA
+CONF_EXEC = CP MKDIR RM RMR FIND SUDO PDFTEX TEXI2PDF TEXI2HTML MAKEINFO INSTALL_INFO
+CONF_CALL = BATCH BATCHL ELCDIR BTEST MAKE_LOCAL_MK MAKE_ORG_INSTALL MAKE_ORG_VERSION
+config-eol:: EOL = \#
+config-eol:: config-all
+config config-all::
+	$(info )
+	$(info ========= Emacs executable and Installation paths)
+	$(foreach var,$(CONF_BASE),$(info $(var)	= $($(var))$(EOL)))
+config-test config-all::
+	$(info )
+	$(info ========= Test configuration)
+	$(foreach var,$(CONF_TEST),$(info $(var)	= $($(var))$(EOL)))
+config-exe config-all::
+	$(info )
+	$(info ========= Executables used by make)
+	$(foreach var,$(CONF_EXEC),$(info $(var)	= $($(var))$(EOL)))
+config-cmd config-all::
+	$(info )
+	$(info ========= Commands used by make)
+	$(foreach var,$(CONF_CALL),$(info $(var)	= $($(var))$(EOL)))
+config config-test config-exe config-all::
+	$(info )
 
 oldorg:	compile info	# what the old makefile did when no target was specified
 uncompiled:	cleanlisp autoloads	# for developing